http://www.sciencedaily.com/releases/2009/05/090528133423.htm
ScienceDaily (May 29, 2009) — Researchers from the University of California at Davis (USA) and the Max Planck Institute for Evolutionary Anthropology in Leipzig (Germany) present a virtual reconstruction of a female Neanderthal pelvis from Tabun (Israel).
Although the size of Tabun’s reconstructed birth canal shows that Neanderthal childbirth was about as difficult as in present-day humans, the shape indicates that Neanderthals retained a more primitive birth mechanism than modern humans. The virtual reconstruction of the pelvis from Tabun is going to be the first of its kind to be available for download on the internet for everyone interested in the evolution of humankind (PNAS, April 20th, 2009).
Childbirth in humans is more complicated than in other primates. Unlike the situation in great apes, human babies are about the same size as the birth canal, making passage difficult. The birth mechanism, a series of rotations the baby must undergo to successfully navigate its mother’s birth canal, distinguishes humans not only from great apes but also from lesser apes and monkeys.
It has been difficult to trace the evolution of human childbirth because the pelvic skeleton, which forms the margins of the birth canal, tends to survive poorly in the fossil record. Only three fossil female individuals preserve fairly complete birth canals, and they all date to earlier phases of human evolution.
Tim Weaver of the University of California (Davis, USA) and Jean-Jacques Hublin, director at the Max Planck Institute for Evolutionary Anthropology in Leipzig (Germany) now present a virtual reconstruction of a female Neanderthal pelvis from Tabun (Israel). The size of Tabun’s reconstructed birth canal shows that Neanderthal childbirth was about as difficult as in present-day humans. However, its shape indicates that Neanderthals retained a more primitive birth mechanism than modern humans, without rotation of the baby’s body.
A significant shift in childbirth apparently happened quite late in human evolution, during the last 400,000 - 300,000 years. Such a late shift underscores the uniqueness of human childbirth and the divergent evolutionary trajectories of Neanderthals and the lineage leading to present-day humans.
The virtual reconstruction of the pelvis from Tabun is going to be the first of its kind to be available for download on the internet for everyone interested in human evolution. The computer files will be available from the websites of University of California at Davis and the Max Planck Institute for Evolutionary Anthropology.
Friday, May 29, 2009
Male Or Female? Coloring Provides Gender Cues
http://www.sciencedaily.com/releases/2009/05/090527121049.htm
ScienceDaily (May 28, 2009) — Our brain is wired to identify gender based on facial cues and coloring, according to a new study published in the Journal of Vision. Psychology Professor Frédéric Gosselin and his Université de Montréal team found the luminescence of the eyebrow and mouth region is vital in rapid gender discrimination.
"As teenagers, dimorphism (systematic difference between sexes) increases in the nose, chin, mouth, jaw, eyes and general shape of faces," says Nicolas Dupuis-Roy, lead author of the study. "Yet we aren't conscious of how our brain recognizes those differences."
To discover those reference points, Dupuis-Roy and colleagues showed photos of 300 Caucasian faces to some 30 participants. Subjects were asked to identify gender based on images where parts of faces were concealed using a technology called Bubbles.
The investigation found that eyes and mouths, specifically their subtle shading or luminance, are paramount in identifying gender. Unlike previous studies, which found the gap between the eyelid and eyebrow as essential in gender ID, this investigation found the shades of reds and greens around mouths and eyes led to faster gender discrimination.
"Studies have shown that an androgynous face is considered male if the skin complexion is redder, and considered female if the complexion is greener," says Dupuis-Roy. "However, it is the opposite for the mouth. A woman's mouth is usually redder. Our brain interprets this characteristic as female."
"A man's face usually reflects less light around the eyebrows. This is because they are usually thicker. The same applies to the upper lip and chin, which are hairier areas," he adds, noting people clearly use colour to rapidly identify gender.
This research was supported by the Fonds québécois de la recherche sur la nature et les technologies and Natural Sciences and Engineering Research Council of Canada. PhD student Isabelle Fortin and Professor Daniel Fiset also participated in the study.
ScienceDaily (May 28, 2009) — Our brain is wired to identify gender based on facial cues and coloring, according to a new study published in the Journal of Vision. Psychology Professor Frédéric Gosselin and his Université de Montréal team found the luminescence of the eyebrow and mouth region is vital in rapid gender discrimination.
"As teenagers, dimorphism (systematic difference between sexes) increases in the nose, chin, mouth, jaw, eyes and general shape of faces," says Nicolas Dupuis-Roy, lead author of the study. "Yet we aren't conscious of how our brain recognizes those differences."
To discover those reference points, Dupuis-Roy and colleagues showed photos of 300 Caucasian faces to some 30 participants. Subjects were asked to identify gender based on images where parts of faces were concealed using a technology called Bubbles.
The investigation found that eyes and mouths, specifically their subtle shading or luminance, are paramount in identifying gender. Unlike previous studies, which found the gap between the eyelid and eyebrow as essential in gender ID, this investigation found the shades of reds and greens around mouths and eyes led to faster gender discrimination.
"Studies have shown that an androgynous face is considered male if the skin complexion is redder, and considered female if the complexion is greener," says Dupuis-Roy. "However, it is the opposite for the mouth. A woman's mouth is usually redder. Our brain interprets this characteristic as female."
"A man's face usually reflects less light around the eyebrows. This is because they are usually thicker. The same applies to the upper lip and chin, which are hairier areas," he adds, noting people clearly use colour to rapidly identify gender.
This research was supported by the Fonds québécois de la recherche sur la nature et les technologies and Natural Sciences and Engineering Research Council of Canada. PhD student Isabelle Fortin and Professor Daniel Fiset also participated in the study.
Thursday, May 28, 2009
Money Worries Make Women Spend More
http://www.sciencedaily.com/releases/2009/05/090521084834.htm
Money Worries Make Women Spend More
ScienceDaily (May 23, 2009) — At times of crisis women are more inclined to spend themselves out of misery than at stable times, a new survey suggests. Psychologists say that the recession could force more women to overspend or increase their risk of mental illness.
A survey conducted by Professor Karen Pine, from the University of Hertfordshire and author of Sheconomics, to be released on 21 May 2009 found that 79% of women said they would go on a spending spree to cheer themselves up. Professor Pine’s research concludes that some women use shopping as an emotion regulator, a way of anesthetising themselves to negative feelings or dissatisfaction with life. So worrying about money could, paradoxically, lead women to spend more.
Of the 700 women surveyed, four out of ten named ‘depression’, and six out of ten named ‘feeling a bit low’, as reasons to go on a spending spree and overspend. Women commonly expressed the view that shopping has the power to make them feel better.
Professor Pine’s research found that an intense emotional state, high or low, could send women to the shops. “This type of spending, or compensatory consumption, serves as a way of regulating intense emotions,” she said.
This ability to regulate emotions is crucial for mental and physical wellbeing and humans adopt a variety of means of doing so, including drugs and alcohol. Shopping is one method increasingly adopted by women.
“If shopping is an emotional habit for women they may feel the need to keep spending despite the economic downturn,” said Professor Pine. “Or, perhaps worse still, if they can’t spend we might see an increase in mental health problems such as anxiety and depression.”
Not all the women in the survey felt cheered up by the shopping experience. One in four had experienced feelings of regret, guilt or shame after buying something in the week prior to the survey. And seven out of ten women had worried about money during the same period. Yet if these women shop when feeling down they risk getting trapped in a vicious cycle of highs and lows akin to that found in other addictions.
I don't have strong feelings about this either way, what is it about spending that helps women regulate negative emotions? Perhaps the short term joy from new objects is enough to regular superficial emotions. If worrying causes depression which says something in your environment is off, then buying something to fix your environment could help. What would be the evolutionary equivalent of shopping?
Money Worries Make Women Spend More
ScienceDaily (May 23, 2009) — At times of crisis women are more inclined to spend themselves out of misery than at stable times, a new survey suggests. Psychologists say that the recession could force more women to overspend or increase their risk of mental illness.
A survey conducted by Professor Karen Pine, from the University of Hertfordshire and author of Sheconomics, to be released on 21 May 2009 found that 79% of women said they would go on a spending spree to cheer themselves up. Professor Pine’s research concludes that some women use shopping as an emotion regulator, a way of anesthetising themselves to negative feelings or dissatisfaction with life. So worrying about money could, paradoxically, lead women to spend more.
Of the 700 women surveyed, four out of ten named ‘depression’, and six out of ten named ‘feeling a bit low’, as reasons to go on a spending spree and overspend. Women commonly expressed the view that shopping has the power to make them feel better.
Professor Pine’s research found that an intense emotional state, high or low, could send women to the shops. “This type of spending, or compensatory consumption, serves as a way of regulating intense emotions,” she said.
This ability to regulate emotions is crucial for mental and physical wellbeing and humans adopt a variety of means of doing so, including drugs and alcohol. Shopping is one method increasingly adopted by women.
“If shopping is an emotional habit for women they may feel the need to keep spending despite the economic downturn,” said Professor Pine. “Or, perhaps worse still, if they can’t spend we might see an increase in mental health problems such as anxiety and depression.”
Not all the women in the survey felt cheered up by the shopping experience. One in four had experienced feelings of regret, guilt or shame after buying something in the week prior to the survey. And seven out of ten women had worried about money during the same period. Yet if these women shop when feeling down they risk getting trapped in a vicious cycle of highs and lows akin to that found in other addictions.
I don't have strong feelings about this either way, what is it about spending that helps women regulate negative emotions? Perhaps the short term joy from new objects is enough to regular superficial emotions. If worrying causes depression which says something in your environment is off, then buying something to fix your environment could help. What would be the evolutionary equivalent of shopping?
Opposites Attract: How Genetics Influences Humans To Choose Their Mates
http://www.sciencedaily.com/releases/2009/05/090525105435.htm
ScienceDaily (May 25, 2009) — New light has been thrown on how humans choose their partners, according to new findings presented May 25 at the annual conference of the European Society of Human Genetics.
Professor Maria da Graça Bicalho, head of the Immunogenetics and Histocompatibility Laboratory at the University of Parana, Brazil, says that her research had shown that people with diverse major histocompatibility complexes (MHCs) were more likely to choose each other as mates than those whose MHCs were similar, and that this was likely to be an evolutionary strategy to ensure healthy reproduction.
The MHC is a large genetic region situated on chromosome 6, and found in most vertebrates. It plays an important role in the immune system and also in reproductive success. Apart from being a large region, it is also an extraordinarily diverse one.
Females' preference for MHC dissimilar mates has been shown in many vertebrate species, including humans, and it is also known that MHC influences mating selection by preferences for particular body odours. The Brazilian team has been working in this field since 1998, and decided to investigate mate selection in the Brazilian population, while trying to uncover the biological significance of MHC diversity.
The scientists studied MHC data from 90 married couples, and compared them with 152 randomly-generated control couples. They counted the number of MHC dissimilarities among those who were real couples, and compared them with those in the randomly-generated 'virtual couples'. "If MHC genes did not influence mate selection", says Professor Bicalho, "we would have expected to see similar results from both sets of couples. But we found that the real partners had significantly more MHC dissimilarities than we could have expected to find simply by chance."
Within MHC-dissimilar couples the partners will be genetically different, and such a pattern of mate choice decreases the danger of endogamy (mating among relatives) and increases the genetic variability of offspring. Genetic variability is known to be an advantage for offspring, and the MHC effect could be an evolutionary strategy underlying incest avoidance in humans and also improving the efficiency of the immune system, the scientists say.
"Although it may be tempting to think that humans choose their partners because of their similarities", says Professor Bicalho, "our research has shown clearly that it is differences that make for successful reproduction, and that the subconscious drive to have healthy children is important when choosing a mate."
The scientists believe that their findings will help understanding of conception, fertility, and gestational failures. Research has already shown that couples with similar MHC genes had longer intervals between births, which could imply early, unperceived miscarriages. "We intend to follow up this work by looking at social and cultural influences as well as biological ones in mate choice, and relating these to the genetic diversity of the extended MHC region", says Professor Bicalho.
"We expect to find that cultural aspects play an important role in mate choice, and certainly do not subscribe to the theory that if a person bears a particular genetic variant it will determine his or her behaviour. But we also think that the unconscious evolutionary aspect of partner choice should not be overlooked. We believe our research shows that this has an important role to play in ensuring healthy reproduction, by helping to ensure that children are born with a strong immune system better able to cope with infection."
ScienceDaily (May 25, 2009) — New light has been thrown on how humans choose their partners, according to new findings presented May 25 at the annual conference of the European Society of Human Genetics.
Professor Maria da Graça Bicalho, head of the Immunogenetics and Histocompatibility Laboratory at the University of Parana, Brazil, says that her research had shown that people with diverse major histocompatibility complexes (MHCs) were more likely to choose each other as mates than those whose MHCs were similar, and that this was likely to be an evolutionary strategy to ensure healthy reproduction.
The MHC is a large genetic region situated on chromosome 6, and found in most vertebrates. It plays an important role in the immune system and also in reproductive success. Apart from being a large region, it is also an extraordinarily diverse one.
Females' preference for MHC dissimilar mates has been shown in many vertebrate species, including humans, and it is also known that MHC influences mating selection by preferences for particular body odours. The Brazilian team has been working in this field since 1998, and decided to investigate mate selection in the Brazilian population, while trying to uncover the biological significance of MHC diversity.
The scientists studied MHC data from 90 married couples, and compared them with 152 randomly-generated control couples. They counted the number of MHC dissimilarities among those who were real couples, and compared them with those in the randomly-generated 'virtual couples'. "If MHC genes did not influence mate selection", says Professor Bicalho, "we would have expected to see similar results from both sets of couples. But we found that the real partners had significantly more MHC dissimilarities than we could have expected to find simply by chance."
Within MHC-dissimilar couples the partners will be genetically different, and such a pattern of mate choice decreases the danger of endogamy (mating among relatives) and increases the genetic variability of offspring. Genetic variability is known to be an advantage for offspring, and the MHC effect could be an evolutionary strategy underlying incest avoidance in humans and also improving the efficiency of the immune system, the scientists say.
"Although it may be tempting to think that humans choose their partners because of their similarities", says Professor Bicalho, "our research has shown clearly that it is differences that make for successful reproduction, and that the subconscious drive to have healthy children is important when choosing a mate."
The scientists believe that their findings will help understanding of conception, fertility, and gestational failures. Research has already shown that couples with similar MHC genes had longer intervals between births, which could imply early, unperceived miscarriages. "We intend to follow up this work by looking at social and cultural influences as well as biological ones in mate choice, and relating these to the genetic diversity of the extended MHC region", says Professor Bicalho.
"We expect to find that cultural aspects play an important role in mate choice, and certainly do not subscribe to the theory that if a person bears a particular genetic variant it will determine his or her behaviour. But we also think that the unconscious evolutionary aspect of partner choice should not be overlooked. We believe our research shows that this has an important role to play in ensuring healthy reproduction, by helping to ensure that children are born with a strong immune system better able to cope with infection."
Wednesday, May 27, 2009
Some People Really 'Never Forget A Face:' Understanding Extraordinary Face Recognition Ability
http://www.sciencedaily.com/releases/2009/05/090519172204.htm
ScienceDaily (May 20, 2009) — Some people say they never forget a face, a claim now bolstered by psychologists at Harvard University who've discovered a group they call "super-recognizers": those who can easily recognize someone they met in passing, even many years later.
The new study suggests that skill in facial recognition might vary widely among humans. Previous research has identified as much as 2 percent of the population as having "face-blindness," or prosopagnosia, a condition characterized by great difficulty in recognizing faces. For the first time, this new research shows that others excel in face recognition, indicating that the trait could be on a spectrum, with prosopagnosics on the low end and super-recognizers at the high end.
The research is published in Psychonomic Bulletin & Review, and was led by Richard Russell, a postdoctoral researcher in the Department of Psychology at Harvard, with co-authors Ken Nakayama, Edgar Pierce Professor of Psychology at Harvard, and Brad Duchaine of the University College London.
The research involved administering standardized face recognition tests. The super-recognizers scored far above average on these tests—higher than any of the normal control subjects.
"There has been a default assumption that there is either normal face recognition, or there is disordered face recognition," says Russell. "This suggests that's not the case, that there is actually a very wide range of ability. It suggests a different model—a different way of thinking about face recognition ability, and possibly even other aspects of perception, in terms of a spectrum of abilities, rather than there being normal and disordered ability."
Super-recognizers report that they recognize other people far more often than they are recognized. For this reason, says Russell, they often compensate by pretending not to recognize someone they met in passing, so as to avoid appearing to attribute undue importance to a fleeting encounter.
"Super-recognizers have these extreme stories of recognizing people," says Russell. "They recognize a person who was shopping in the same store with them two months ago, for example, even if they didn't speak to the person. It doesn't have to be a significant interaction; they really stand out in terms of their ability to remember the people who were actually less significant."
One woman in the study said she had identified another woman on the street who served as her as a waitress five years earlier in a different city. Critically, she was able to confirm that the other woman had in fact been a waitress in the different city. Often, super-recognizers are able to recognize another person despite significant changes in appearance, such as aging or a different hair color.
If face recognition abilities do vary, testing for this may be important for assessing eyewitness testimony, or for interviewing for some jobs, such as security or those checking identification.
Russell theorizes that super-recognizers and those with face-blindness may only be distinguishable today because our communities differ from how they existed thousands of years ago.
"Until recently, most humans lived in much smaller communities, with many fewer people interacting on a regular basis within a group," says Russell. "It may be a fairly new phenomenon that there's even a need to recognize large numbers of people."
The research was funded by the U.S. National Eye Institute and the U.K. Economic and Social Research Council
Interesting, a new ability based on our current living situations and not our past ones. I can see how this wouldn't be beneficial in the past with exposure to such few people, and why it would be favored in our current situation.
ScienceDaily (May 20, 2009) — Some people say they never forget a face, a claim now bolstered by psychologists at Harvard University who've discovered a group they call "super-recognizers": those who can easily recognize someone they met in passing, even many years later.
The new study suggests that skill in facial recognition might vary widely among humans. Previous research has identified as much as 2 percent of the population as having "face-blindness," or prosopagnosia, a condition characterized by great difficulty in recognizing faces. For the first time, this new research shows that others excel in face recognition, indicating that the trait could be on a spectrum, with prosopagnosics on the low end and super-recognizers at the high end.
The research is published in Psychonomic Bulletin & Review, and was led by Richard Russell, a postdoctoral researcher in the Department of Psychology at Harvard, with co-authors Ken Nakayama, Edgar Pierce Professor of Psychology at Harvard, and Brad Duchaine of the University College London.
The research involved administering standardized face recognition tests. The super-recognizers scored far above average on these tests—higher than any of the normal control subjects.
"There has been a default assumption that there is either normal face recognition, or there is disordered face recognition," says Russell. "This suggests that's not the case, that there is actually a very wide range of ability. It suggests a different model—a different way of thinking about face recognition ability, and possibly even other aspects of perception, in terms of a spectrum of abilities, rather than there being normal and disordered ability."
Super-recognizers report that they recognize other people far more often than they are recognized. For this reason, says Russell, they often compensate by pretending not to recognize someone they met in passing, so as to avoid appearing to attribute undue importance to a fleeting encounter.
"Super-recognizers have these extreme stories of recognizing people," says Russell. "They recognize a person who was shopping in the same store with them two months ago, for example, even if they didn't speak to the person. It doesn't have to be a significant interaction; they really stand out in terms of their ability to remember the people who were actually less significant."
One woman in the study said she had identified another woman on the street who served as her as a waitress five years earlier in a different city. Critically, she was able to confirm that the other woman had in fact been a waitress in the different city. Often, super-recognizers are able to recognize another person despite significant changes in appearance, such as aging or a different hair color.
If face recognition abilities do vary, testing for this may be important for assessing eyewitness testimony, or for interviewing for some jobs, such as security or those checking identification.
Russell theorizes that super-recognizers and those with face-blindness may only be distinguishable today because our communities differ from how they existed thousands of years ago.
"Until recently, most humans lived in much smaller communities, with many fewer people interacting on a regular basis within a group," says Russell. "It may be a fairly new phenomenon that there's even a need to recognize large numbers of people."
The research was funded by the U.S. National Eye Institute and the U.K. Economic and Social Research Council
Interesting, a new ability based on our current living situations and not our past ones. I can see how this wouldn't be beneficial in the past with exposure to such few people, and why it would be favored in our current situation.
People By Nature Are Universally Optimistic, Study Shows
http://www.sciencedaily.com/releases/2009/05/090524122539.htm
ScienceDaily (May 25, 2009) — Despite calamities from economic recessions, wars and famine to a flu epidemic afflicting the Earth, a new study from the University of Kansas and Gallup indicates that humans are by nature optimistic.
The study, to be presented May 24, 2009, at the annual meeting of the Association for Psychological Science in San Francisco, found optimism to be universal and borderless.
Data from the Gallup World Poll drove the findings, with adults in more than 140 countries providing a representative sample of 95 percent of the world's population. The sample included more than 150,000 adults.
Eighty-nine percent of individuals worldwide expect the next five years to be as good or better than their current life, and 95 percent of individuals expected their life in five years to be as good or better than their life was five years ago.
"These results provide compelling evidence that optimism is a universal phenomenon," said Matthew Gallagher, a psychology doctoral candidate at the University of Kansas and lead researcher of the study.
At the country level, optimism is highest in Ireland, Brazil, Denmark, and New Zealand and lowest in Zimbabwe, Egypt, Haiti and Bulgaria. The United States ranks number 10 on the list of optimistic countries.
Demographic factors (age and household income) appear to have only modest effects on individual levels of optimism.
ScienceDaily (May 25, 2009) — Despite calamities from economic recessions, wars and famine to a flu epidemic afflicting the Earth, a new study from the University of Kansas and Gallup indicates that humans are by nature optimistic.
The study, to be presented May 24, 2009, at the annual meeting of the Association for Psychological Science in San Francisco, found optimism to be universal and borderless.
Data from the Gallup World Poll drove the findings, with adults in more than 140 countries providing a representative sample of 95 percent of the world's population. The sample included more than 150,000 adults.
Eighty-nine percent of individuals worldwide expect the next five years to be as good or better than their current life, and 95 percent of individuals expected their life in five years to be as good or better than their life was five years ago.
"These results provide compelling evidence that optimism is a universal phenomenon," said Matthew Gallagher, a psychology doctoral candidate at the University of Kansas and lead researcher of the study.
At the country level, optimism is highest in Ireland, Brazil, Denmark, and New Zealand and lowest in Zimbabwe, Egypt, Haiti and Bulgaria. The United States ranks number 10 on the list of optimistic countries.
Demographic factors (age and household income) appear to have only modest effects on individual levels of optimism.
Rich Man, Poor Man: Body Language Can Indicate Socioeconomic Status, Study Shows
http://www.sciencedaily.com/releases/2009/02/090204121515.htm
ScienceDaily (Feb. 5, 2009) — Socioeconomic status (SES) is determined by a number of factors such as wealth, occupation and schools attended. SES influences the food we eat, hobbies we participate in and can even have an impact on our health.
People with an upper SES background can often be accused of flaunting their status, such as by the types of cars they drive or how many pairs of Manolo Blahniks they have in their closet. It is easy to guess someone's SES based on their clothing and the size of their home, but what about more subtle clues? Psychologists Michael W. Kraus and Dacher Keltner of the University of California, Berkeley wanted to see if non-verbal cues (that is, body language) can indicate our SES.
To test this idea, the researchers videotaped participants as they got to know one another in one-on-one interview sessions. During these taped sessions, the researchers looked for two types of behaviors: disengagement behaviors (including fidgeting with personal objects and doodling) and engagement behaviors (including head nodding, laughing and eye contact).
The results, reported in Psychological Science, reveal that nonverbal cues can give away a person's SES. Volunteers whose parents were from upper SES backgrounds displayed more disengagement-related behaviors compared to participants from lower SES backgrounds. In addition, when a separate group of observers were shown 60 second clips of the videos, they were able to correctly guess the participants' SES background, based on their body language.
The researchers note that this is the first study to show a relation between SES and social engagement behavior. They surmise that people from upper SES backgrounds who are wealthy and have access to prestigious institutions tend to be less dependent on others. "This lack of dependence among upper SES people is displayed in their nonverbal behaviors during social interactions," the psychologists conclude.
Journal reference:
Kraus et al. Signs of Socioeconomic Status: A Thin-Slicing Approach. Psychological Science, 2009; 20 (1): 99 DOI: 10.1111/j.1467-9280.2008.02251.x
I think it's not only interesting that we unconsciously (maybe even consciously) portray our SES by body language, but that the participants were able to correctly identify their standing with 100 percent accuracy. I can see how it would be beneficial to show a wealthy status but to also evolve to pick up on those cues. Also their conclusion makes a lot of sense as well, why would you need to keep broadening your social circle if you don't need more support? It's actually probably a hindrance to keep attracting more people who may need your resources. I can see the good side and bad side of advertising your SES, and this study helps support the idea that it's more beneficial to display it.
ScienceDaily (Feb. 5, 2009) — Socioeconomic status (SES) is determined by a number of factors such as wealth, occupation and schools attended. SES influences the food we eat, hobbies we participate in and can even have an impact on our health.
People with an upper SES background can often be accused of flaunting their status, such as by the types of cars they drive or how many pairs of Manolo Blahniks they have in their closet. It is easy to guess someone's SES based on their clothing and the size of their home, but what about more subtle clues? Psychologists Michael W. Kraus and Dacher Keltner of the University of California, Berkeley wanted to see if non-verbal cues (that is, body language) can indicate our SES.
To test this idea, the researchers videotaped participants as they got to know one another in one-on-one interview sessions. During these taped sessions, the researchers looked for two types of behaviors: disengagement behaviors (including fidgeting with personal objects and doodling) and engagement behaviors (including head nodding, laughing and eye contact).
The results, reported in Psychological Science, reveal that nonverbal cues can give away a person's SES. Volunteers whose parents were from upper SES backgrounds displayed more disengagement-related behaviors compared to participants from lower SES backgrounds. In addition, when a separate group of observers were shown 60 second clips of the videos, they were able to correctly guess the participants' SES background, based on their body language.
The researchers note that this is the first study to show a relation between SES and social engagement behavior. They surmise that people from upper SES backgrounds who are wealthy and have access to prestigious institutions tend to be less dependent on others. "This lack of dependence among upper SES people is displayed in their nonverbal behaviors during social interactions," the psychologists conclude.
Journal reference:
Kraus et al. Signs of Socioeconomic Status: A Thin-Slicing Approach. Psychological Science, 2009; 20 (1): 99 DOI: 10.1111/j.1467-9280.2008.02251.x
I think it's not only interesting that we unconsciously (maybe even consciously) portray our SES by body language, but that the participants were able to correctly identify their standing with 100 percent accuracy. I can see how it would be beneficial to show a wealthy status but to also evolve to pick up on those cues. Also their conclusion makes a lot of sense as well, why would you need to keep broadening your social circle if you don't need more support? It's actually probably a hindrance to keep attracting more people who may need your resources. I can see the good side and bad side of advertising your SES, and this study helps support the idea that it's more beneficial to display it.
Psychologists Find That Head Movement Is More Important Than Gender In Nonverbal Communication
http://www.sciencedaily.com/releases/2009/05/090525105459.htm
ScienceDaily (May 26, 2009) — It is well known that people use head motion during conversation to convey a range of meanings and emotions, and that women use more active head motion when conversing with each other than men use when they talk with each other.
When men and women converse together, the men use a little more head motion and the women use a little less. But the men and women might be adapting because of their gender-based expectations or because of the movements they perceive from each other.
What would happen if you could change the apparent gender of a conversant while keeping all of the motion dynamics of head movement and facial expression?
Using new videoconferencing technology, a team of psychologists and computer scientists – led by Steven Boker, a professor of psychology at the University of Virginia – were able to switch the apparent gender of study participants during conversation and found that head motion was more important than gender in determining how people coordinate with each other while engaging in conversation.
The scientists found that gender-based social expectations are unlikely to be the source of reported gender differences in the way people coordinate their head movements during two-way conversation.
The researchers used synthesized faces – known as avatars – in video-conferences with naïve participants, who believed they were conversing onscreen with an actual person rather than a synthetic version of a person.
In some conversations, the researchers changed the gender of the avatars and the vocal pitch of the avatar's voice – while still maintaining their actual head movements and facial expressions – convincing naïve participants that they were speaking with, for example, a male when they were in fact speaking with a female, or vice versa.
"We found that people simply adapt to each other's head movements and facial expressions, regardless of the apparent sex of the person they are talking to," Boker said. "This is important because it indicates that how you appear is less important than how you move when it comes to what other people feel when they speak with you."
He presented the findings May 24 at the annual convention of the Association for Psychological Science in San Francisco. A paper detailing the results is scheduled for publication in the Journal of Experimental Psychology: Human Perception and Performance.
The study, funded by the National Science Foundation, used a low-bandwidth, high-frame-rate videoconferencing technology to record and recreate facial expressions to see how people alter their behavior based on the slightest changes in expression of another person. The U.Va.-based team also includes researchers at the University of Pittsburgh, University of East Anglia, Carnegie Mellon University and Disney Research.
A video demonstration is available online at: http://faculty.virginia.edu/humandynamicslab/.
The technology uses statistical representations of a person's face to track and reconstruct that face. This allows the principal components of facial expression – only dozens in number – to be transmitted as a close rendition of the actual face. It's a sort of connect-the-dots fabrication that can be transmitted frame by frame in near-real time.
Boker and his team are trying to understand how people interact during conversation, and how factors such as gender or race may alter the dynamics of a conversation. To do so, they needed a way to capture facial expressions people use when conversing.
"From a psychological standpoint, our interest is in how people interact and how they coordinate their facial expressions as they talk with one another, such as when one person nods while speaking, or listening, the other person likewise nods," Boker said.
It is this "mirroring process" of coordination that helps people to feel a connection with each other.
"When I coordinate my facial expressions or head movements with yours, I activate a system that helps me empathize with your feelings," Boker said.
The technology the team developed further allows them to map the facial expressions of one person onto the face of another in a real time videoconference. In this way they can change the apparent gender or race of a participant and closely track how a naïve participant reacts when speaking to a woman, say, as opposed to a man.
"In this way we can distinguish between how people coordinate their facial expressions and what their social expectation is," Boker said.
This is absolutely amazing to me that we are so intuned to head motion that we can be tricked into perceiving another gender. I guess this exists because the more intuned you are the better your social relations are and therfore are more likely to survive.
ScienceDaily (May 26, 2009) — It is well known that people use head motion during conversation to convey a range of meanings and emotions, and that women use more active head motion when conversing with each other than men use when they talk with each other.
When men and women converse together, the men use a little more head motion and the women use a little less. But the men and women might be adapting because of their gender-based expectations or because of the movements they perceive from each other.
What would happen if you could change the apparent gender of a conversant while keeping all of the motion dynamics of head movement and facial expression?
Using new videoconferencing technology, a team of psychologists and computer scientists – led by Steven Boker, a professor of psychology at the University of Virginia – were able to switch the apparent gender of study participants during conversation and found that head motion was more important than gender in determining how people coordinate with each other while engaging in conversation.
The scientists found that gender-based social expectations are unlikely to be the source of reported gender differences in the way people coordinate their head movements during two-way conversation.
The researchers used synthesized faces – known as avatars – in video-conferences with naïve participants, who believed they were conversing onscreen with an actual person rather than a synthetic version of a person.
In some conversations, the researchers changed the gender of the avatars and the vocal pitch of the avatar's voice – while still maintaining their actual head movements and facial expressions – convincing naïve participants that they were speaking with, for example, a male when they were in fact speaking with a female, or vice versa.
"We found that people simply adapt to each other's head movements and facial expressions, regardless of the apparent sex of the person they are talking to," Boker said. "This is important because it indicates that how you appear is less important than how you move when it comes to what other people feel when they speak with you."
He presented the findings May 24 at the annual convention of the Association for Psychological Science in San Francisco. A paper detailing the results is scheduled for publication in the Journal of Experimental Psychology: Human Perception and Performance.
The study, funded by the National Science Foundation, used a low-bandwidth, high-frame-rate videoconferencing technology to record and recreate facial expressions to see how people alter their behavior based on the slightest changes in expression of another person. The U.Va.-based team also includes researchers at the University of Pittsburgh, University of East Anglia, Carnegie Mellon University and Disney Research.
A video demonstration is available online at: http://faculty.virginia.edu/humandynamicslab/.
The technology uses statistical representations of a person's face to track and reconstruct that face. This allows the principal components of facial expression – only dozens in number – to be transmitted as a close rendition of the actual face. It's a sort of connect-the-dots fabrication that can be transmitted frame by frame in near-real time.
Boker and his team are trying to understand how people interact during conversation, and how factors such as gender or race may alter the dynamics of a conversation. To do so, they needed a way to capture facial expressions people use when conversing.
"From a psychological standpoint, our interest is in how people interact and how they coordinate their facial expressions as they talk with one another, such as when one person nods while speaking, or listening, the other person likewise nods," Boker said.
It is this "mirroring process" of coordination that helps people to feel a connection with each other.
"When I coordinate my facial expressions or head movements with yours, I activate a system that helps me empathize with your feelings," Boker said.
The technology the team developed further allows them to map the facial expressions of one person onto the face of another in a real time videoconference. In this way they can change the apparent gender or race of a participant and closely track how a naïve participant reacts when speaking to a woman, say, as opposed to a man.
"In this way we can distinguish between how people coordinate their facial expressions and what their social expectation is," Boker said.
This is absolutely amazing to me that we are so intuned to head motion that we can be tricked into perceiving another gender. I guess this exists because the more intuned you are the better your social relations are and therfore are more likely to survive.
Are Humans Genetically Programmed To Care About Long-term Future And Climate Change?
http://www.sciencedaily.com/releases/2009/05/090527105711.htm
ScienceDaily (May 27, 2009) — Humans may be programmed by evolution to care about the future of the environment, suggests new research.
Dr Peter Sozou suggests that individuals may have an innate tendency to care about the long-term future of their communities, over timescales much longer than an individual’s lifespan. This in turn may help to explain people’s wish to take action over long-term environmental problems.
The findings are published in the Proceedings of the Royal Society B, in a paper entitled "Individual and social discounting in a viscous population."
Dr Sozou, of the University of Warwick’s Medical School and the London School of Economics and Political Science, uses a mathematical model of a population of individuals living in communities with limited migration between them.
The study examines what weight individuals should attach to future benefits. It is shown that the answer depends on whether the future benefits are social benefits for their community or private benefits for themselves. Individuals should be expected to take a long-term view of benefits for their community, but a more short-term view of private benefits to themselves. Humans, like all creatures, generally value a reward today more highly than a reward tomorrow – in other words they discount future benefits. But the model shows that the discount rate is lower for social, rather than individual, benefits.
Dr Sozou said: "This analysis shows that the social discount rate is generally lower than the private discount rate. An individual’s valuation of a future benefit to herself is governed by the probability that she will still be alive in future. But she may value future benefits to her community over a timescale considerably longer than her own lifespan.
"Evolution is driven by competition. Caring about the future of your community makes evolutionary sense to the extent that future members of your community are likely to be your relatives."
However this evolutionary logic does not apply, at first glance, in the case of a global threat such as climate change where the ‘community’, the planet, is not in competition with other communities. "In the absence of this competition," says Dr Sozou, "there is no direct basis for evolution to select behaviours which benefit the planet as a whole, and therefore no evolutionary basis for directly determining a social discount rate for global welfare."
In which case why do we care at all about the long-term future of humanity? The answer, Dr Sozou suggests, is that we have evolved to value social benefits because in our ancestral environment they tended to deliver local benefits – helping our kin to survive. However in the modern age, it is this biological preference for social good which gives us an interest in the future of the planet: "In the modern, global environment, such preferences may cause people to care about global problems such as climate change.
"This issue is particularly important for economics as it has a bearing on decisions about public investments and environmental protection measures - actions which typically involve paying a cost today in order to produce a public benefit tomorrow."
Adapted from materials provided by University of Warwick
ScienceDaily (May 27, 2009) — Humans may be programmed by evolution to care about the future of the environment, suggests new research.
Dr Peter Sozou suggests that individuals may have an innate tendency to care about the long-term future of their communities, over timescales much longer than an individual’s lifespan. This in turn may help to explain people’s wish to take action over long-term environmental problems.
The findings are published in the Proceedings of the Royal Society B, in a paper entitled "Individual and social discounting in a viscous population."
Dr Sozou, of the University of Warwick’s Medical School and the London School of Economics and Political Science, uses a mathematical model of a population of individuals living in communities with limited migration between them.
The study examines what weight individuals should attach to future benefits. It is shown that the answer depends on whether the future benefits are social benefits for their community or private benefits for themselves. Individuals should be expected to take a long-term view of benefits for their community, but a more short-term view of private benefits to themselves. Humans, like all creatures, generally value a reward today more highly than a reward tomorrow – in other words they discount future benefits. But the model shows that the discount rate is lower for social, rather than individual, benefits.
Dr Sozou said: "This analysis shows that the social discount rate is generally lower than the private discount rate. An individual’s valuation of a future benefit to herself is governed by the probability that she will still be alive in future. But she may value future benefits to her community over a timescale considerably longer than her own lifespan.
"Evolution is driven by competition. Caring about the future of your community makes evolutionary sense to the extent that future members of your community are likely to be your relatives."
However this evolutionary logic does not apply, at first glance, in the case of a global threat such as climate change where the ‘community’, the planet, is not in competition with other communities. "In the absence of this competition," says Dr Sozou, "there is no direct basis for evolution to select behaviours which benefit the planet as a whole, and therefore no evolutionary basis for directly determining a social discount rate for global welfare."
In which case why do we care at all about the long-term future of humanity? The answer, Dr Sozou suggests, is that we have evolved to value social benefits because in our ancestral environment they tended to deliver local benefits – helping our kin to survive. However in the modern age, it is this biological preference for social good which gives us an interest in the future of the planet: "In the modern, global environment, such preferences may cause people to care about global problems such as climate change.
"This issue is particularly important for economics as it has a bearing on decisions about public investments and environmental protection measures - actions which typically involve paying a cost today in order to produce a public benefit tomorrow."
Adapted from materials provided by University of Warwick
Is Salt Nature's Antidepressant?
http://news.nationalgeographic.com/news/2009/03/090317-salt-antidepressant.html
Is Salt Nature's Antidepressant?
Helen Fields for National Geographic News
March 17, 2009
He's found that sodium-deprived rats take less pleasure in daily activities—they can't be bothered to drag themselves across the cage to push a bar that releases a dose of sugar water.
But let the rats have salt again and "they're all happy," Johnson said.
Very low sodium in rats, humans, and other land animals may induce something similar to depression—and that eating more salt may make us happier, Johnson thinks.
He points to one study of people with chronic fatigue syndrome. Many of the patients were found to have reduced their sodium intake for health reasons. Increasing sodium in their diets alleviated many of the patients' symptoms.
Land animals have to work constantly to keep their cells bathed in a nice salty solution like the sea our distant ancestors lived in. Our kidneys are beautifully adapted to this task—adjusting the concentration of urine based on how salty the blood is.
But most modern humans eat way more salt than they need.
The brain may continue being happy about salt even when it doesn't strictly need it, in the same way the brain may "reward" us when we eat too much or take dangerous drugs, Johnson said.
So don't start eating sodium-filled frozen dinners to cheer yourself up. The connection between salt and mood is just starting to be fleshed out, but scientists are certain about the link between salt and heart disease.
Depression is an indication when something in our environment is off or a sign to slow down and not spend energy, or an evolved mechanism of distress telling us to hibernate, escape or change something. By approaching this through evolution psychology, this depression after lack of salt makes perfect sense - your body is letting you know something is wrong. In that case, no, salt is not nature's antidepressant (unless the depression has been caused by a lack of salt).
Is Salt Nature's Antidepressant?
Helen Fields for National Geographic News
March 17, 2009
He's found that sodium-deprived rats take less pleasure in daily activities—they can't be bothered to drag themselves across the cage to push a bar that releases a dose of sugar water.
But let the rats have salt again and "they're all happy," Johnson said.
Very low sodium in rats, humans, and other land animals may induce something similar to depression—and that eating more salt may make us happier, Johnson thinks.
He points to one study of people with chronic fatigue syndrome. Many of the patients were found to have reduced their sodium intake for health reasons. Increasing sodium in their diets alleviated many of the patients' symptoms.
Land animals have to work constantly to keep their cells bathed in a nice salty solution like the sea our distant ancestors lived in. Our kidneys are beautifully adapted to this task—adjusting the concentration of urine based on how salty the blood is.
But most modern humans eat way more salt than they need.
The brain may continue being happy about salt even when it doesn't strictly need it, in the same way the brain may "reward" us when we eat too much or take dangerous drugs, Johnson said.
So don't start eating sodium-filled frozen dinners to cheer yourself up. The connection between salt and mood is just starting to be fleshed out, but scientists are certain about the link between salt and heart disease.
Depression is an indication when something in our environment is off or a sign to slow down and not spend energy, or an evolved mechanism of distress telling us to hibernate, escape or change something. By approaching this through evolution psychology, this depression after lack of salt makes perfect sense - your body is letting you know something is wrong. In that case, no, salt is not nature's antidepressant (unless the depression has been caused by a lack of salt).
Want to Live Longer? Stop Worrying
http://news.nationalgeographic.com/news/2009/04/090410-live-longer-neurotic.html
Christine Dell'AmoreNational Geographic News
April 10, 2009
If you want to live to a hundred, you'd better lighten up.
Children of centenarians—who usually inherit both longevity and personality traits from their parents—are on average more outgoing, agreeable, and less neurotic, according to a new study.
That's because being affable and more social confers health benefits, according to lead study author Thomas Perls, director of the New England Centenarian Study at Boston University Medical Center.
It may be that less neurotic people are better able to manage or regulate stressful situations than the highly neurotic, Perls said.
"We've seen centenarians go through huge amounts of stress, and time and time again they've shown us how … it doesn't get to them."
Likable People
The Boston University team gave 246 unrelated children of centenarians a questionnaire that measures neuroticism, extraversion, openness, agreeableness, and conscientiousness.
Rather than directly testing the elderly, the team looked at both male and female offspring who had an average age of 75.
"They're at the stage of their lives when they're cooking along at 110 percent," Perls said. "There's a number of things we can study in them that we can't" in centenarians.
Both males and females scored in the low range for being neurotic and the high range for being extroverted.
Women scored high in agreeableness, while men scored normal. Both sexes tested normal for conscientiousness and openness, according to the study, published in the April issue of the Journal of the American Geriatrics Society.
Buettner has not studied the children of centenarians, though that methodology is "absolutely" valid, he said.
(Buettner has also received funding from the National Geographic Society, which owns National Geographic News.)
In the blue zone of Okinawa, Japan, Buettner asked expert Nobuyoshi Hirose what he thought explains Okinawans' longevity.
"He thought for a moment, and said, They're likable people," Buettner said.
That likeability translates to a robust social circle, one of the common threads among the long-lived, Buettner added.
Improvements
Though many aspects of our personalities are already set by our genes, Buettner said, we can all make lifestyle improvements to help us live longer.
For one, becoming more extroverted—and by extension widening our social networks—can be cultivated and trained, Buettner said.
Also high on his list is eating a plant-based diet—"the more meat you eat, the quicker you die," he said.
And having a clear sense of purpose in your life, he added, is worth seven years of life expectancy.
Study leader Perls added that numerous strategies exist to deal with stress, such as exercising, meditation, or just taking a "nice deep breath."
"It's a matter of setting aside the time and effort to effectively manage your stress well," he said. "One of the keys is to realize how important it is to do that."
While this study does support the theory we were meant to eat a plant based diet, the advice to stop worrying seemed opposite of what I would think to expect. Caution usually equals you spread your genes, but I think this is suggeting that the worrying gets in the way of broadening social networds.
What is it about a large social network that evolution psychology would say extends someone's life? My guesses are resources, support during rough times, a feeling of belonging, or protection from enemies.
Christine Dell'AmoreNational Geographic News
April 10, 2009
If you want to live to a hundred, you'd better lighten up.
Children of centenarians—who usually inherit both longevity and personality traits from their parents—are on average more outgoing, agreeable, and less neurotic, according to a new study.
That's because being affable and more social confers health benefits, according to lead study author Thomas Perls, director of the New England Centenarian Study at Boston University Medical Center.
It may be that less neurotic people are better able to manage or regulate stressful situations than the highly neurotic, Perls said.
"We've seen centenarians go through huge amounts of stress, and time and time again they've shown us how … it doesn't get to them."
Likable People
The Boston University team gave 246 unrelated children of centenarians a questionnaire that measures neuroticism, extraversion, openness, agreeableness, and conscientiousness.
Rather than directly testing the elderly, the team looked at both male and female offspring who had an average age of 75.
"They're at the stage of their lives when they're cooking along at 110 percent," Perls said. "There's a number of things we can study in them that we can't" in centenarians.
Both males and females scored in the low range for being neurotic and the high range for being extroverted.
Women scored high in agreeableness, while men scored normal. Both sexes tested normal for conscientiousness and openness, according to the study, published in the April issue of the Journal of the American Geriatrics Society.
Buettner has not studied the children of centenarians, though that methodology is "absolutely" valid, he said.
(Buettner has also received funding from the National Geographic Society, which owns National Geographic News.)
In the blue zone of Okinawa, Japan, Buettner asked expert Nobuyoshi Hirose what he thought explains Okinawans' longevity.
"He thought for a moment, and said, They're likable people," Buettner said.
That likeability translates to a robust social circle, one of the common threads among the long-lived, Buettner added.
Improvements
Though many aspects of our personalities are already set by our genes, Buettner said, we can all make lifestyle improvements to help us live longer.
For one, becoming more extroverted—and by extension widening our social networks—can be cultivated and trained, Buettner said.
Also high on his list is eating a plant-based diet—"the more meat you eat, the quicker you die," he said.
And having a clear sense of purpose in your life, he added, is worth seven years of life expectancy.
Study leader Perls added that numerous strategies exist to deal with stress, such as exercising, meditation, or just taking a "nice deep breath."
"It's a matter of setting aside the time and effort to effectively manage your stress well," he said. "One of the keys is to realize how important it is to do that."
While this study does support the theory we were meant to eat a plant based diet, the advice to stop worrying seemed opposite of what I would think to expect. Caution usually equals you spread your genes, but I think this is suggeting that the worrying gets in the way of broadening social networds.
What is it about a large social network that evolution psychology would say extends someone's life? My guesses are resources, support during rough times, a feeling of belonging, or protection from enemies.
Night Owls Stay Alert Longer Than Early Birds
http://news.nationalgeographic.com/news/2009/04/090423-night-owls-brains.html
Night Owls Stay Alert Longer Than Early Birds
Anne Minardfor National Geographic News
April 23, 2009
Score one for the night owls—sort of.
Early birds may be chipper in the morning, but they mentally wear out faster, a new brain-scan study reveals.
Scientists monitored the brain activity of self-described early birds and night owls in a sleep lab.
(Related: "Early Risers Have Mutated Gene, Study Says.")
The team, led by Christina Schmidt of the University of Liège in Belgium, also took hourly saliva samples to measure the sleepers' levels of melatonin, a hormone thought to help naturally regulate sleep cycles in mammals.
Both night owls and early birds were allowed to stay on their preferred sleep schedules, but each group was awake for the same number of hours each day.
An hour and a half after waking, the groups scored the same on tests that required them to pay attention to a task.
But ten hours after waking, early birds showed reduced activity in brain areas linked to attention compared with the night owls. The "morning people" also felt sleepier and performed more slowly on tests.
Furthermore, as the day wore on, early birds showed less activity in a region deep in the brain involved in the so-called circadian master clock, which regulates our daily cycles of alertness.
The finding suggests that people tend to favor mornings or nights based at least in part on how they react to a kind of competition in the brain.
Circadian hormones, which keep us alert while awake, can get overridden by sleep pressure, a physiological pull that causes us to get sleepier the longer we're awake.
But while night owls seem to handle sleep pressure better, the late-to-bed strategy might backfire outside the lab, noted study co-author Philippe Peigneux, also of the University of Liège.
"Morning types may be at an advantage, because their schedule is fitting better with the usual work schedule of the society," he said.
"It may represent a problem for evening types obliged to wake up early while having difficulties going to bed in the evening, eventually leading to a sleep debt."
Findings published in this week's issue of the journal Science.
Evolution psychology: why would it have been beneficial for night owls to stay more alert and longer? why would this same alertness not benefit early birds?
My guess is that as the day goes on it gets darker, and therefore those up during those times of decreased light would need to be more alert to danger.
Night Owls Stay Alert Longer Than Early Birds
Anne Minardfor National Geographic News
April 23, 2009
Score one for the night owls—sort of.
Early birds may be chipper in the morning, but they mentally wear out faster, a new brain-scan study reveals.
Scientists monitored the brain activity of self-described early birds and night owls in a sleep lab.
(Related: "Early Risers Have Mutated Gene, Study Says.")
The team, led by Christina Schmidt of the University of Liège in Belgium, also took hourly saliva samples to measure the sleepers' levels of melatonin, a hormone thought to help naturally regulate sleep cycles in mammals.
Both night owls and early birds were allowed to stay on their preferred sleep schedules, but each group was awake for the same number of hours each day.
An hour and a half after waking, the groups scored the same on tests that required them to pay attention to a task.
But ten hours after waking, early birds showed reduced activity in brain areas linked to attention compared with the night owls. The "morning people" also felt sleepier and performed more slowly on tests.
Furthermore, as the day wore on, early birds showed less activity in a region deep in the brain involved in the so-called circadian master clock, which regulates our daily cycles of alertness.
The finding suggests that people tend to favor mornings or nights based at least in part on how they react to a kind of competition in the brain.
Circadian hormones, which keep us alert while awake, can get overridden by sleep pressure, a physiological pull that causes us to get sleepier the longer we're awake.
But while night owls seem to handle sleep pressure better, the late-to-bed strategy might backfire outside the lab, noted study co-author Philippe Peigneux, also of the University of Liège.
"Morning types may be at an advantage, because their schedule is fitting better with the usual work schedule of the society," he said.
"It may represent a problem for evening types obliged to wake up early while having difficulties going to bed in the evening, eventually leading to a sleep debt."
Findings published in this week's issue of the journal Science.
Evolution psychology: why would it have been beneficial for night owls to stay more alert and longer? why would this same alertness not benefit early birds?
My guess is that as the day goes on it gets darker, and therefore those up during those times of decreased light would need to be more alert to danger.
Fatty Foods May Boost Memory
http://news.nationalgeographic.com/news/2009/04/090427-fat-memory.html
Ker Than for National Geographic News
April 27, 2009
Feeling forgetful? Munch on a fatty snack.
A hormone released during the digestion of certain fats triggers long-term memory formation in rats, a new study says.
Researchers found that administering a compound produced in the small intestine called oleoylethanolamide (OEA) to rats improved memory retention during two different tasks.
When cell receptors activated by OEA were blocked, the animals' performance decreased.
Though the study involved rats, OEA's effects should be similar in other animals, including humans, said study team member Daniele Piomelli, a neuroscientist at the University of California, Irvine.
Follow the Fat
The team suspects OEA's memory-enhancing activity likely evolved to help animals remember where and when they ate a fatty meal, so they could return to that spot later.
Fats are crucial for a variety of biological functions and structures. While the modern human diet is now rich in fats, such foods are actually rare in nature.
"It makes sense that nature evolved a system for strengthening memories associated with the places and context where fats are gathered," Piomelli told National Geographic News.
While Piomelli doesn't recommend that people binge on fast food to improve memory, his team's findings could explain why kids who eat breakfast and mid-morning snacks generally perform better in school.
"Studies show that it's not because they learn better, but because they remember better," Piomelli said.
In the future, scientists could use OEA or OEA-like compounds as medicines to boost memory or treat diseases that affect memory.
(Explore an interactive brain.)
"One idea would be to [use drugs] to activate the same receptor that OEA activates, or perhaps give nutrition that produces enough OEA to cause the same [memory] effect," Piomelli said.
The research is detailed this week in Proceedings of the National Academy of Sciences.
Ker Than for National Geographic News
April 27, 2009
Feeling forgetful? Munch on a fatty snack.
A hormone released during the digestion of certain fats triggers long-term memory formation in rats, a new study says.
Researchers found that administering a compound produced in the small intestine called oleoylethanolamide (OEA) to rats improved memory retention during two different tasks.
When cell receptors activated by OEA were blocked, the animals' performance decreased.
Though the study involved rats, OEA's effects should be similar in other animals, including humans, said study team member Daniele Piomelli, a neuroscientist at the University of California, Irvine.
Follow the Fat
The team suspects OEA's memory-enhancing activity likely evolved to help animals remember where and when they ate a fatty meal, so they could return to that spot later.
Fats are crucial for a variety of biological functions and structures. While the modern human diet is now rich in fats, such foods are actually rare in nature.
"It makes sense that nature evolved a system for strengthening memories associated with the places and context where fats are gathered," Piomelli told National Geographic News.
While Piomelli doesn't recommend that people binge on fast food to improve memory, his team's findings could explain why kids who eat breakfast and mid-morning snacks generally perform better in school.
"Studies show that it's not because they learn better, but because they remember better," Piomelli said.
In the future, scientists could use OEA or OEA-like compounds as medicines to boost memory or treat diseases that affect memory.
(Explore an interactive brain.)
"One idea would be to [use drugs] to activate the same receptor that OEA activates, or perhaps give nutrition that produces enough OEA to cause the same [memory] effect," Piomelli said.
The research is detailed this week in Proceedings of the National Academy of Sciences.
Weaklings' Sharper Hearing Helps Them Escape Danger?
Weaklings' Sharper Hearing Helps Them Escape Danger?
Brian Handwerkfor National Geographic News
May 15, 2009
http://news.nationalgeographic.com/news/2009/05/090515-weakling-hearing.html
Human weaklings have evolved a sharper sense of hearing that gives them advance notice when trouble is coming, according to a new study.
The research revealed that to the less physically fit, approaching sounds are more likely to sound closer than they really are.
Scientists first studied how men hear looming sounds that steadily approach the listener.
Most respondents—regardless of their fitness—believe the sources of such sounds have reached them before they actually have. This adaptation may help humans sense and escape danger.
"If you err on the side of safety, that genetic characteristic will be passed on,"
said lead study author John Neuhoff, an evolutionary psychologist at the College of Wooster in Ohio.
But people with wimpy physiques—who lack the strength to overpower threats or the cardiovascular fitness to outrun them—display more extreme versions of the auditory alarm system.
"If you're physically fit, you can react quickly. So you don't need as much of a margin of safety as you would if you were a typical couch potato," Neuhoff explained.
(Explore an interactive on human evolution.)
Mind Control
Previous research has shown that women also responded to looming sounds more quickly than men, who would typically have a physical advantage.
Neuhoff said his team plans to examine possible links between a host of physical characteristics that may be important for dealing with threats. He noted that the mind also plays a large role.
"There are a lot of things that contribute to how much room for error you need," he said.
"We've shown that physical fitness is one thing that contributes, but things like your personality or your propensity for risk-taking could also be factors."
Neuhoff presents his findings next week at the Acoustical Society of America Meeting in Portland, Oregon.
Brian Handwerkfor National Geographic News
May 15, 2009
http://news.nationalgeographic.com/news/2009/05/090515-weakling-hearing.html
Human weaklings have evolved a sharper sense of hearing that gives them advance notice when trouble is coming, according to a new study.
The research revealed that to the less physically fit, approaching sounds are more likely to sound closer than they really are.
Scientists first studied how men hear looming sounds that steadily approach the listener.
Most respondents—regardless of their fitness—believe the sources of such sounds have reached them before they actually have. This adaptation may help humans sense and escape danger.
"If you err on the side of safety, that genetic characteristic will be passed on,"
said lead study author John Neuhoff, an evolutionary psychologist at the College of Wooster in Ohio.
But people with wimpy physiques—who lack the strength to overpower threats or the cardiovascular fitness to outrun them—display more extreme versions of the auditory alarm system.
"If you're physically fit, you can react quickly. So you don't need as much of a margin of safety as you would if you were a typical couch potato," Neuhoff explained.
(Explore an interactive on human evolution.)
Mind Control
Previous research has shown that women also responded to looming sounds more quickly than men, who would typically have a physical advantage.
Neuhoff said his team plans to examine possible links between a host of physical characteristics that may be important for dealing with threats. He noted that the mind also plays a large role.
"There are a lot of things that contribute to how much room for error you need," he said.
"We've shown that physical fitness is one thing that contributes, but things like your personality or your propensity for risk-taking could also be factors."
Neuhoff presents his findings next week at the Acoustical Society of America Meeting in Portland, Oregon.
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