http://www.sciencedaily.com/releases/2009/06/090618180334.htm
ScienceDaily (July 8, 2009) — Darwin's theory of evolution predicts that men will take more care of children that look like them. A team at the Institut des sciences de l'évolution (CNRS / Université de Montpellier 2) verified this prediction in a study published online in the pre-print issue of the journal Animal Behaviour.
The investment of a father in the care and education of a child is a decisive factor for the child's development, growth and even survival, particularly in countries with high infant mortality. As this behavior is transmitted from generation to generation, it can evolve by natural selection. Evolutionary theory predicts that men should have developed the capacity to recognise their biological children. This recognition of paternity can be made on the basis of physical resemblance.
The study by the ISEM(1) team has shown for the first time that paternal investment is partly influenced by genetically based similarities.
The study was conducted in several villages in Senegal, where the researchers used a method that simultaneously quantified investment made by fathers and their resemblance to their children. A total of thirty families, each with two children, took part in the study. To quantify paternal investment, mothers answered a questionnaire in which they had to estimate the time that the father spent looking after the child, his attention, affection and even the money he provided.
According to their answers, each father was assigned an investment index. A separate group of people, who did not know these families, were chosen as relatedness 'raters' to evaluate facial and olfactory resemblance between children and fathers. For the faces, a photograph of each child was shown to the raters, together with those of three men including the father. For odor, the evaluator had to compare the odors of a tee-shirt worn by the child with those of two men. Each time that the father was recognized, a point was attributed and these results were collated to build a resemblance index.
A correlation was found between these resemblance indices and the paternal investment as calculated from the questionnaire results. The study also clearly confirmed the positive impact of a father's presence on the nutrition and growth of the child. In this region, children who benefit from the presence of their father clearly have better living conditions.
From the point of view of Darwinian theory, very few studies have been made on the link between paternal investment and genetically based resemblance, and none have been done with real families. Today, these results represent an important step in the study of the evolution of paternal investment. The ISEM team has also conducted a study on paternal investment in France from which results will be published in the coming months.
1) Institut des sciences de l'évolution de Montpellier (CNRS / Université de Montpellier)
Journal reference:
Alvergne et al. Father-offspring resemblance predicts paternal investment in humans. Animal Behaviour, May 28, 2009; DOI: 10.1016/j.anbehav.2009.03.019
Wednesday, July 8, 2009
When Young Men Are Scarce, They're More Likely To Play The Field Than To Propose
When Young Men Are Scarce, They're More Likely To Play The Field Than To Propose
ScienceDaily (June 10, 2009) — In places where young women outnumber young men, research shows the hemlines rise but the marriage rates don't because the young men feel less pressure to settle down as more women compete for their affections.
But when those men reach their 30s, the reverse is true and proportionately more older men are married in areas where women outnumber men.
Daniel Kruger, a University of Michigan researcher who studies evolution and how it relates to contemporary behavior, looked at the 50 largest metropolitan areas in the United States to test his hypothesis on how the balance between women and men affects marital patterns. Results showed that men aged 20-24 are more likely to cruise than to commit if they live in an area with more women than men.
One would think that rationally, fewer young men than women would naturally lead to proportionately more young men getting married, but that's not the case.
"Marriage patterns aren't rational because men and women have somewhat different reproductive strategies," Kruger said. "Men have a greater reproductive benefit than women from having a greater quantity of relationships. If they can leverage their scarcity into attracting multiple short-term partners, they will not have as much of an incentive to settle down."
There are about nine unmarried men for every 10 unmarried women in Birmingham, Memphis, New Orleans, and Richmond-Petersburg, Virginia, Kruger says. Philadelphia, Washington, DC, Baltimore, and New York metropolitan areas are tied for the next region where women are relatively most plentiful. In these areas, about 84 percent of the men aged 20-24 are unmarried. In Las Vegas, San Diego, Salt Lake City, Austin, and Phoenix, there are about nine unmarried women for every 10 unmarried men. In these areas, about 77 percent of the men aged 20-24 are unmarried.
Once those young men hit their 30s, they tend to shift from seeking short-term relationships to entering into committed relationships. That's because when women evaluate partners for short-term relationships they value physical features signaling the kind of genes that would be passed on to potential offspring, which may be the only legacy of men who don't stick around for child rearing. These physical features decline as men age, making it more difficult to lure women into uncommitted relationships.
"You see a complete reversal in the pattern," Kruger said, and thus, proportionately more older men are married when women outnumber men.
So, does this mean that middle aged women in these cities get a break? Not really, Kruger says. The higher marital rates for older men likely benefit women who are substantially younger than their husbands, because older men still prefer partners with higher reproductive potential.
The ratio of men to women has other aspects, as well. For instance, studies have shown that when women outnumber men, hemlines actually rise, overall, as women to do more to physically attract men. Also, the rates of divorce and out-of-wedlock births are higher, and interests in women's rights increases. Surpluses of men tend to be associated with more conservative social norms and restricted roles for women.
ScienceDaily (June 10, 2009) — In places where young women outnumber young men, research shows the hemlines rise but the marriage rates don't because the young men feel less pressure to settle down as more women compete for their affections.
But when those men reach their 30s, the reverse is true and proportionately more older men are married in areas where women outnumber men.
Daniel Kruger, a University of Michigan researcher who studies evolution and how it relates to contemporary behavior, looked at the 50 largest metropolitan areas in the United States to test his hypothesis on how the balance between women and men affects marital patterns. Results showed that men aged 20-24 are more likely to cruise than to commit if they live in an area with more women than men.
One would think that rationally, fewer young men than women would naturally lead to proportionately more young men getting married, but that's not the case.
"Marriage patterns aren't rational because men and women have somewhat different reproductive strategies," Kruger said. "Men have a greater reproductive benefit than women from having a greater quantity of relationships. If they can leverage their scarcity into attracting multiple short-term partners, they will not have as much of an incentive to settle down."
There are about nine unmarried men for every 10 unmarried women in Birmingham, Memphis, New Orleans, and Richmond-Petersburg, Virginia, Kruger says. Philadelphia, Washington, DC, Baltimore, and New York metropolitan areas are tied for the next region where women are relatively most plentiful. In these areas, about 84 percent of the men aged 20-24 are unmarried. In Las Vegas, San Diego, Salt Lake City, Austin, and Phoenix, there are about nine unmarried women for every 10 unmarried men. In these areas, about 77 percent of the men aged 20-24 are unmarried.
Once those young men hit their 30s, they tend to shift from seeking short-term relationships to entering into committed relationships. That's because when women evaluate partners for short-term relationships they value physical features signaling the kind of genes that would be passed on to potential offspring, which may be the only legacy of men who don't stick around for child rearing. These physical features decline as men age, making it more difficult to lure women into uncommitted relationships.
"You see a complete reversal in the pattern," Kruger said, and thus, proportionately more older men are married when women outnumber men.
So, does this mean that middle aged women in these cities get a break? Not really, Kruger says. The higher marital rates for older men likely benefit women who are substantially younger than their husbands, because older men still prefer partners with higher reproductive potential.
The ratio of men to women has other aspects, as well. For instance, studies have shown that when women outnumber men, hemlines actually rise, overall, as women to do more to physically attract men. Also, the rates of divorce and out-of-wedlock births are higher, and interests in women's rights increases. Surpluses of men tend to be associated with more conservative social norms and restricted roles for women.
Risky Business: Stressed Men, But Not Stressed Women, More Likely To Gamble And Takes Risks
http://www.sciencedaily.com/releases/2009/06/090630202123.htm
ScienceDaily (July 1, 2009) — Stressed out, dude? Don't go to Vegas.
New research, to be published July 1 in the journal PLoS One, shows that men under stress may be more likely to take risks, correlating to such real-life behavior as gambling, smoking, unsafe sex and illegal drug use.
In contrast, stressed women moderate their behavior and may be less likely to make risky choices, the study found.
"Evolutionarily speaking, it's perhaps more beneficial for men to be aggressive in stressful, high-arousal situations when risk and reward are involved," said Nichole Lighthall of the University of Southern California Davis School of Gerontology and lead author of the paper. "Applied to financial risk taking, it's akin to competition for territory or other valuable resources."
The researchers asked participants to play a game called the Balloon Analogue Risk Task in which inflating a balloon earns money (five cents per pump). Participants were told that they could cash out their earnings by clicking a "Collect $$$" button at any point in the game.
However, the balloon would explode if it was inflated beyond its randomly determined breakpoint. All winnings for exploded balloons would be lost.
"One valuable aspect of the [balloon task] is its predictive validity for real-world impulsivity," Lighthall explained. "Some risk taking was necessary to make gains, but excessive risk was associated with diminishing returns. If you always clicked and never cashed out, you would lose every time."
The balloon task has been previously used to assess tolerance for risky behavior among inner-city adolescents and substance abusers, among others.
"Obviously, there are situations in the real world where risky behavior would not be beneficial," Lighthall said. "Sometimes being conservative, thoughtful and taking it slow are good things."
In the control group, men and women displayed statistically similar levels of risk taking, inflating the balloon about 40 times on average.
However, women in the stressed group only inflated the balloon an average of 32 times – more than 30 percent less often than their stressed male counterparts, who inflated the balloon an average of 48 times.
"Men seem to enter more risky financial situations than women, which was part of the impetus for our study," Lighthall said. "But only in the stressed condition did we see any statistical differences in risky behavior between men and women."
Stressful experiences have been shown to stimulate the release of cortisol, commonly known as the "stress hormone." Participants randomly assigned to the stress group held a hand in ice-cold water, which raised cortisol levels, particularly among female participants. No participants were using hormone birth control.
According to Lighthall, future research might use neuroimaging to explore how the brain processes stress or examine whether psychological stress, such as anticipating giving a speech, would yield similar results as the physical stress manipulation used in this study.
Mara Mather, director of the Emotion and Cognition Lab at USC and associate professor of psychology and gerontology at the USC Davis School of Gerontology, and Marissa Gorlick, also of the USC Davis School of Gerontology, were co-authors of the study.
Adapted from materials provided by University of Southern California, via EurekAlert!, a service of AAAS.
ScienceDaily (July 1, 2009) — Stressed out, dude? Don't go to Vegas.
New research, to be published July 1 in the journal PLoS One, shows that men under stress may be more likely to take risks, correlating to such real-life behavior as gambling, smoking, unsafe sex and illegal drug use.
In contrast, stressed women moderate their behavior and may be less likely to make risky choices, the study found.
"Evolutionarily speaking, it's perhaps more beneficial for men to be aggressive in stressful, high-arousal situations when risk and reward are involved," said Nichole Lighthall of the University of Southern California Davis School of Gerontology and lead author of the paper. "Applied to financial risk taking, it's akin to competition for territory or other valuable resources."
The researchers asked participants to play a game called the Balloon Analogue Risk Task in which inflating a balloon earns money (five cents per pump). Participants were told that they could cash out their earnings by clicking a "Collect $$$" button at any point in the game.
However, the balloon would explode if it was inflated beyond its randomly determined breakpoint. All winnings for exploded balloons would be lost.
"One valuable aspect of the [balloon task] is its predictive validity for real-world impulsivity," Lighthall explained. "Some risk taking was necessary to make gains, but excessive risk was associated with diminishing returns. If you always clicked and never cashed out, you would lose every time."
The balloon task has been previously used to assess tolerance for risky behavior among inner-city adolescents and substance abusers, among others.
"Obviously, there are situations in the real world where risky behavior would not be beneficial," Lighthall said. "Sometimes being conservative, thoughtful and taking it slow are good things."
In the control group, men and women displayed statistically similar levels of risk taking, inflating the balloon about 40 times on average.
However, women in the stressed group only inflated the balloon an average of 32 times – more than 30 percent less often than their stressed male counterparts, who inflated the balloon an average of 48 times.
"Men seem to enter more risky financial situations than women, which was part of the impetus for our study," Lighthall said. "But only in the stressed condition did we see any statistical differences in risky behavior between men and women."
Stressful experiences have been shown to stimulate the release of cortisol, commonly known as the "stress hormone." Participants randomly assigned to the stress group held a hand in ice-cold water, which raised cortisol levels, particularly among female participants. No participants were using hormone birth control.
According to Lighthall, future research might use neuroimaging to explore how the brain processes stress or examine whether psychological stress, such as anticipating giving a speech, would yield similar results as the physical stress manipulation used in this study.
Mara Mather, director of the Emotion and Cognition Lab at USC and associate professor of psychology and gerontology at the USC Davis School of Gerontology, and Marissa Gorlick, also of the USC Davis School of Gerontology, were co-authors of the study.
Adapted from materials provided by University of Southern California, via EurekAlert!, a service of AAAS.
Rating Attractiveness: Consensus Among Men, Not Women, Study Finds
http://www.sciencedaily.com/releases/2009/06/090626153511.htm
Rating Attractiveness: Consensus Among Men, Not Women, Study Finds
ScienceDaily (June 27, 2009) — Hot or not? Men agree on the answer. Women don't.
There is much more consensus among men about whom they find attractive than there is among women, according to a new study by Wake Forest University psychologist Dustin Wood.
The study, co-authored by Claudia Brumbaugh of Queens College, appears in the June issue of the Journal of Personality and Social Psychology.
"Men agree a lot more about who they find attractive and unattractive than women agree about who they find attractive and unattractive," says Wood, assistant professor of psychology. "This study shows we can quantify the extent to which men agree about which women are attractive and vice versa."
More than 4,000 participants in the study rated photographs of men and women (ages 18-25) for attractiveness on a 10-point scale ranging from "not at all" to "very." In exchange for their participation, raters were told what characteristics they found attractive compared with the average person. The raters ranged in age from 18 to more than 70.
Before the participants judged the photographs for attractiveness, the members of the research team rated the images for how seductive, confident, thin, sensitive, stylish, curvaceous (women), muscular (men), traditional, masculine/feminine, classy, well-groomed, or upbeat the people looked.
Breaking out these factors helped the researchers figure out what common characteristics appealed most to women and men.
Men's judgments of women's attractiveness were based primarily around physical features and they rated highly those who looked thin and seductive. Most of the men in the study also rated photographs of women who looked confident as more attractive.
As a group, the women rating men showed some preference for thin, muscular subjects, but disagreed on how attractive many men in the study were. Some women gave high attractiveness ratings to the men other women said were not attractive at all.
"As far as we know, this is the first study to investigate whether there are differences in the level of consensus male and female raters have in their attractiveness judgments," Wood says. "These differences have implications for the different experiences and strategies that could be expected for men and women in the dating marketplace."
For example, women may encounter less competition from other women for the men they find attractive, he says. Men may need to invest more time and energy in attracting and then guarding their mates from other potential suitors, given that the mates they judge attractive are likely to be found attractive by many other men.
Wood says the study results have implications for eating disorders and how expectations regarding attractiveness affect behavior.
"The study helps explain why women experience stronger norms than men to obtain or maintain certain physical characteristics," he says. "Women who are trying to impress men are likely to be found much more attractive if they meet certain physical standards, and much less if they don't. Although men are rated as more attractive by women when they meet these physical appearance standards too, their overall judged attractiveness isn't as tightly linked to their physical features."
The age of the participants also played a role in attractiveness ratings. Older participants were more likely to find people attractive if they were smiling.
Rating Attractiveness: Consensus Among Men, Not Women, Study Finds
ScienceDaily (June 27, 2009) — Hot or not? Men agree on the answer. Women don't.
There is much more consensus among men about whom they find attractive than there is among women, according to a new study by Wake Forest University psychologist Dustin Wood.
The study, co-authored by Claudia Brumbaugh of Queens College, appears in the June issue of the Journal of Personality and Social Psychology.
"Men agree a lot more about who they find attractive and unattractive than women agree about who they find attractive and unattractive," says Wood, assistant professor of psychology. "This study shows we can quantify the extent to which men agree about which women are attractive and vice versa."
More than 4,000 participants in the study rated photographs of men and women (ages 18-25) for attractiveness on a 10-point scale ranging from "not at all" to "very." In exchange for their participation, raters were told what characteristics they found attractive compared with the average person. The raters ranged in age from 18 to more than 70.
Before the participants judged the photographs for attractiveness, the members of the research team rated the images for how seductive, confident, thin, sensitive, stylish, curvaceous (women), muscular (men), traditional, masculine/feminine, classy, well-groomed, or upbeat the people looked.
Breaking out these factors helped the researchers figure out what common characteristics appealed most to women and men.
Men's judgments of women's attractiveness were based primarily around physical features and they rated highly those who looked thin and seductive. Most of the men in the study also rated photographs of women who looked confident as more attractive.
As a group, the women rating men showed some preference for thin, muscular subjects, but disagreed on how attractive many men in the study were. Some women gave high attractiveness ratings to the men other women said were not attractive at all.
"As far as we know, this is the first study to investigate whether there are differences in the level of consensus male and female raters have in their attractiveness judgments," Wood says. "These differences have implications for the different experiences and strategies that could be expected for men and women in the dating marketplace."
For example, women may encounter less competition from other women for the men they find attractive, he says. Men may need to invest more time and energy in attracting and then guarding their mates from other potential suitors, given that the mates they judge attractive are likely to be found attractive by many other men.
Wood says the study results have implications for eating disorders and how expectations regarding attractiveness affect behavior.
"The study helps explain why women experience stronger norms than men to obtain or maintain certain physical characteristics," he says. "Women who are trying to impress men are likely to be found much more attractive if they meet certain physical standards, and much less if they don't. Although men are rated as more attractive by women when they meet these physical appearance standards too, their overall judged attractiveness isn't as tightly linked to their physical features."
The age of the participants also played a role in attractiveness ratings. Older participants were more likely to find people attractive if they were smiling.
Friday, June 19, 2009
NO-FATHERS DAY: Remote Group Has No Dads, And Never Did
http://news.nationalgeographic.com/news/2009/06/090619-fathers-day-2009-no-fathers.html
NO-FATHERS DAY: Remote Group Has No Dads, And Never Did
Brian Handwerkfor National Geographic News
June 18, 2009
What would Father's Day—and every other day—be like without fathers? Maybe not so bad, according to experts on the Mosuo culture of the Chinese Himalaya.
The women of this matrilineal society shun marriage and raise their kids in homes with their entire extended families—but no dads.
By most accounts, children seem to do just fine under the arrangement.
"They are a society that we know hasn't had marriage for a thousand years, and they've been able to raise kids successfully," said Stephanie Coontz, family studies professor at the Evergreen State College in Olympia, Washington.
No Fathers: It Makes Genetic Sense?
Men of the Mosuo, who live around Lugu Lake on the border between Yunnan and Sichuan Provinces, do help to raise kids—just not their own, with whom the men typically have only limited relationships.
Instead the men help look after all the children born to their own sisters, aunts, and other women of the family.
Rather than "one father with a kid, it will be four or five uncles. That [father] role is shared among a number of people, and these are very large extended families," explained John Lombard, director of the Lugu Lake Mosuo Cultural Development Association.
The unusual parenting arrangement makes genetic sense, in terms of extending the family line—and many Mosuo men actually think of it that way, Lombard said.
"If you [father] a child with another woman, you can never be absolutely sure that the child really shares your genes," he said. "But if your sister has a child, you can be 100 percent sure that the kid shares some of your genes."
The women of the Mosuo's agricultural villages head the households, make business decisions, and own property, which they pass on to their matrilineal heirs.
In the unique Mosuo tradition called the walking marriage, women invite men to visit their rooms at night—and to leave in the morning.
Women may also change partners as often as they like, and promiscuity carries no social stigma. The practice has made the Mosuo famous, particularly to male Chinese tourists, many of whom see the walking marriages as evidence of sexual liberation and wanton lust, experts say. Though there are tourist-oriented brothels in Mosuo villages, most are staffed with non-Mosuo women and are considered shameful by the Mosuo, according to the the Lugu Lake Mosuo Cultural Development Association Web site.
"I think sometimes the media gets carried away with the possibility that the women can have all these husbands," said filmmaker Xiaoli Zhou, who produced and reported the 2006 documentary on the Mosuo, The Women's Kingdom.
In fact, most Mosuo women don't change walking-marriage partners very frequently. And they rarely carry on more than one romantic relationship at a time.
"Many of the women I interviewed had only had one or two relationships in their lives," Zhou said.
Family First
The lack of live-in fathers shouldn't be taken as evidence that the Mosuo don't value family life, said Lombard, of the Lugu Lake Mosuo Cultural Development Association.
In fact, they value it above all other relationships—particularly those founded on the sometimes fickle feelings of male-female amour, he said.
Extended families of siblings, uncles, aunts, and others are said to be extremely stable, Lombard added.
For example, there are no divorces to destablize the families. And even the death of a child's biological father has little effect on the family, given the father's distance from the family and the extensive support network in the household.
Brent Huffman, co-producer of The Women's Kingdom, said, "The society does kind of create this question: Are fathers really necessary?
"It's hard to think of in Western society, but there, it works."
NO-FATHERS DAY: Remote Group Has No Dads, And Never Did
Brian Handwerkfor National Geographic News
June 18, 2009
What would Father's Day—and every other day—be like without fathers? Maybe not so bad, according to experts on the Mosuo culture of the Chinese Himalaya.
The women of this matrilineal society shun marriage and raise their kids in homes with their entire extended families—but no dads.
By most accounts, children seem to do just fine under the arrangement.
"They are a society that we know hasn't had marriage for a thousand years, and they've been able to raise kids successfully," said Stephanie Coontz, family studies professor at the Evergreen State College in Olympia, Washington.
No Fathers: It Makes Genetic Sense?
Men of the Mosuo, who live around Lugu Lake on the border between Yunnan and Sichuan Provinces, do help to raise kids—just not their own, with whom the men typically have only limited relationships.
Instead the men help look after all the children born to their own sisters, aunts, and other women of the family.
Rather than "one father with a kid, it will be four or five uncles. That [father] role is shared among a number of people, and these are very large extended families," explained John Lombard, director of the Lugu Lake Mosuo Cultural Development Association.
The unusual parenting arrangement makes genetic sense, in terms of extending the family line—and many Mosuo men actually think of it that way, Lombard said.
"If you [father] a child with another woman, you can never be absolutely sure that the child really shares your genes," he said. "But if your sister has a child, you can be 100 percent sure that the kid shares some of your genes."
The women of the Mosuo's agricultural villages head the households, make business decisions, and own property, which they pass on to their matrilineal heirs.
In the unique Mosuo tradition called the walking marriage, women invite men to visit their rooms at night—and to leave in the morning.
Women may also change partners as often as they like, and promiscuity carries no social stigma. The practice has made the Mosuo famous, particularly to male Chinese tourists, many of whom see the walking marriages as evidence of sexual liberation and wanton lust, experts say. Though there are tourist-oriented brothels in Mosuo villages, most are staffed with non-Mosuo women and are considered shameful by the Mosuo, according to the the Lugu Lake Mosuo Cultural Development Association Web site.
"I think sometimes the media gets carried away with the possibility that the women can have all these husbands," said filmmaker Xiaoli Zhou, who produced and reported the 2006 documentary on the Mosuo, The Women's Kingdom.
In fact, most Mosuo women don't change walking-marriage partners very frequently. And they rarely carry on more than one romantic relationship at a time.
"Many of the women I interviewed had only had one or two relationships in their lives," Zhou said.
Family First
The lack of live-in fathers shouldn't be taken as evidence that the Mosuo don't value family life, said Lombard, of the Lugu Lake Mosuo Cultural Development Association.
In fact, they value it above all other relationships—particularly those founded on the sometimes fickle feelings of male-female amour, he said.
Extended families of siblings, uncles, aunts, and others are said to be extremely stable, Lombard added.
For example, there are no divorces to destablize the families. And even the death of a child's biological father has little effect on the family, given the father's distance from the family and the extensive support network in the household.
Brent Huffman, co-producer of The Women's Kingdom, said, "The society does kind of create this question: Are fathers really necessary?
"It's hard to think of in Western society, but there, it works."
Having A Higher Purpose In Life Reduces Risk Of Death Among Older Adults
http://www.sciencedaily.com/releases/2009/06/090615144207.htm
ScienceDaily (June 18, 2009) — Possessing a greater purpose in life is associated with lower mortality rates among older adults according to a new study by researchers at Rush University Medical Center.
Patricia A. Boyle, PhD, and her colleagues from the Rush Alzheimer’s Disease Center, studied 1,238 community-dwelling elderly participants from two ongoing research studies, the Rush Memory and Aging Project and the Minority Aging Research Study. None had dementia. Data from baseline evaluations of purpose in life and up to five years of follow-up were used to test the hypothesis that greater purpose in life is associated with a reduced risk of mortality among community-dwelling older persons.
Purpose in life reflects the tendency to derive meaning from life’s experiences and be focused and intentional, according to Boyle.
After adjusting for age, sex, education and race, a higher purpose of life was associated with a substantially reduced risk of mortality. Thus, a person with high purpose in life was about half as likely to die over the follow-up period compared to a person with low purpose. The association of purpose in life with mortality did not differ among men and women or whites and blacks, and the finding persisted even after controlling for depressive symptoms, disability, neuroticism, the number of medical conditions and income. During the study period, 151 participants died.
“The finding that purpose in life is related to longevity in older persons suggests that aspects of human flourishing—particularly the tendency to derive meaning from life’s experiences and possess a sense of intentionality and goal-directedness—contribute to successful aging,” said Boyle.
Significant associations with mortality were found with three specific items on the purpose of life questionnaire to determine the study participants’ agreement with the following statements: “I sometimes feel as if I’ve done all there is to do in life;” “I used to set goals for myself, but that now seems like a waste of time;” and “My daily activities often seem trivial and unimportant to me.”
“We are excited about these findings because they suggest that positive factors such as having a sense of purpose in life are important contributors to health,” said Boyle.
The researchers note that knowledge of the relationship of purpose of life with other demographic characteristics is limited and future studies are needed to examine whether the association of purpose of life with mortality might be modified by other variables not measured in this study, such as how religious a participant may be. In addition, researchers suggest that future studies should examine whether purpose in life can be enhanced in older persons with interventions.
“Although we think that having a sense of purpose in life is important across the lifespan, measurement of purpose in life in older persons in particular may reveal an enduring sense of meaningfulness and intentionality in life that somehow provides a buffer against negative health outcomes,” said Boyle.
The Rush Memory and Aging Project, which began in 1997, is a longitudinal clinical-pathological study of common chronic conditions of aging. Participants are older persons recruited from about 40 continuous care retirement communities and senior subsidized housing facilities in and around the Chicago Metropolitan area. More than 1,200 older persons are enrolled in the study.
The Minority Aging Research Study began in 2004 and is a study of risk factors for cognitive decline in older Blacks. Participants are recruited from community-based organizations, churches, and senior subsidized housing facilities in and around the Chicago Metropolitan Area. More than 350 older persons are enrolled in the study.
The study is published in Psychosomatic Medicine.
Adapted from materials provided by Rush University Medical Center.
ScienceDaily (June 18, 2009) — Possessing a greater purpose in life is associated with lower mortality rates among older adults according to a new study by researchers at Rush University Medical Center.
Patricia A. Boyle, PhD, and her colleagues from the Rush Alzheimer’s Disease Center, studied 1,238 community-dwelling elderly participants from two ongoing research studies, the Rush Memory and Aging Project and the Minority Aging Research Study. None had dementia. Data from baseline evaluations of purpose in life and up to five years of follow-up were used to test the hypothesis that greater purpose in life is associated with a reduced risk of mortality among community-dwelling older persons.
Purpose in life reflects the tendency to derive meaning from life’s experiences and be focused and intentional, according to Boyle.
After adjusting for age, sex, education and race, a higher purpose of life was associated with a substantially reduced risk of mortality. Thus, a person with high purpose in life was about half as likely to die over the follow-up period compared to a person with low purpose. The association of purpose in life with mortality did not differ among men and women or whites and blacks, and the finding persisted even after controlling for depressive symptoms, disability, neuroticism, the number of medical conditions and income. During the study period, 151 participants died.
“The finding that purpose in life is related to longevity in older persons suggests that aspects of human flourishing—particularly the tendency to derive meaning from life’s experiences and possess a sense of intentionality and goal-directedness—contribute to successful aging,” said Boyle.
Significant associations with mortality were found with three specific items on the purpose of life questionnaire to determine the study participants’ agreement with the following statements: “I sometimes feel as if I’ve done all there is to do in life;” “I used to set goals for myself, but that now seems like a waste of time;” and “My daily activities often seem trivial and unimportant to me.”
“We are excited about these findings because they suggest that positive factors such as having a sense of purpose in life are important contributors to health,” said Boyle.
The researchers note that knowledge of the relationship of purpose of life with other demographic characteristics is limited and future studies are needed to examine whether the association of purpose of life with mortality might be modified by other variables not measured in this study, such as how religious a participant may be. In addition, researchers suggest that future studies should examine whether purpose in life can be enhanced in older persons with interventions.
“Although we think that having a sense of purpose in life is important across the lifespan, measurement of purpose in life in older persons in particular may reveal an enduring sense of meaningfulness and intentionality in life that somehow provides a buffer against negative health outcomes,” said Boyle.
The Rush Memory and Aging Project, which began in 1997, is a longitudinal clinical-pathological study of common chronic conditions of aging. Participants are older persons recruited from about 40 continuous care retirement communities and senior subsidized housing facilities in and around the Chicago Metropolitan area. More than 1,200 older persons are enrolled in the study.
The Minority Aging Research Study began in 2004 and is a study of risk factors for cognitive decline in older Blacks. Participants are recruited from community-based organizations, churches, and senior subsidized housing facilities in and around the Chicago Metropolitan Area. More than 350 older persons are enrolled in the study.
The study is published in Psychosomatic Medicine.
Adapted from materials provided by Rush University Medical Center.
Wednesday, June 17, 2009
"Human"-Faced Missing Link Found in Spain?
http://news.nationalgeographic.com/news/2009/06/090610-missing-link-human-face.html
James Owen for National Geographic News
June 10, 2009
Move over Ida—you're last month's news. There's a new (purported) "missing link" in town.
An 11.9-million-year-old fossil ape species with an unusually flat, "surprisingly human" face has been found in Spain. The discovery suggests humans' ape ancestors split from primitive apes in Europe, not Africa—the so-called cradle of humanity—a new study says.
The species, Anoiapithecus brevirostris, may also represent the last known common ancestor of humans and living great apes—including orangutans, gorillas, and chimpanzees—researchers say.
"With this fossil, our opinion is that the origin of our family very probably took place in the Mediterranean region," said study leader Salvador Moyà-Solà of the Catalan Institute of Paleontology in Barcelona.
"Surprisingly Human"
Unearthed at a fossil-rich site near Barcelona in 2004, the fragmented skull remains suggest a species with human-like facial features, Moyà-Solà said.
But a familiar face in and of itself doesn't mean the fossil "has any special specific relationship with modern hominds"—humans and the great apes—the paleontologist added.
Rather, the human-like face is evidence of great diversity among ape species in the Mediterranean region 12 million years ago, he said.
Missing Link?
Resembling both primitive ape species and our early ancestors, Anoiapithecus could be called a missing link.
The ape's wide nose and long palate, for example, resemble those of the ancient apes from which great apes and humans arose, the study says.
But Anoiapithecus' thickly enameled teeth and robust jaw are like those of primitive Kenyapithecus fossil apes, which lived in both Africa and Europe, according to the team.
Kenyapithecus species have been proposed as common ancestors of humans and great apes.
Until now, however, there hasn't been a fossil linking Kenyapithecus to later apes thought to have evolved into more direct human ancestors, according to the study, published last week in the journal Proceedings of the National Academy of Sciences.
The Spanish ape suggests this key evolutionary transition occurred after Kenyapithecus arrived in Europe from Africa some 15 million years ago—likely crossing over before the Mediterranean Sea formed, separating Africa from Europe—Moyà-Solà said.
"The 'folks' that migrated from Africa to the Mediterranean area were in fact completely primitive, without the [hominid] features that identify the members of our family," he said.
"The ancestors of gorillas, chimps, and humans then went back to Africa close to some nine million years ago."
There, they would give rise to the first humans, the thinking goes.
European Interlude
The new study isn't the first to hint at a European origin for hominids.
A similar theory has been advanced, for instance, based on 10- to 13-million-year-old fossils of the chimplike Dryopithecus group from France, Hungary, and Spain.
Anthropologist David Begun of the University of Toronto believes the evolution of African apes can be traced to Dryopithecus species that had migrated from Africa to Europe during the pre-Mediterranean Sea period.
"The new Spanish fossils do indeed support that hypothesis," said Begun, who was not involved in the new study and whose work has been partially funded by the National Geographic Society's Committee for Research and Exploration. (The National Geographic Society owns National Geographic News.)
However Begun "does not see any compelling evidence" linking Kenyapithecus with the newfound Spanish species.
"Frankly, [the new species] does not look like Kenyapithecus to me," he added.
Moyà-Solà, the study leader, doesn't rule out the possibility that each of the great ape species evolved independently from different Kenyapithecus species.
And it's possible that Africa could yet yield a species that, like the new Spanish ape, bridges the gap between early human ancestors and more primitive apes, he admitted.
"It's impossible to test our hypothesis [as of yet], because the fossil record in Africa from this period is very poor," Moyà-Solà said. "We need more and better fossils from Africa."
To that end, he said, the team's next major scientific stop will be somewhere south of the Mediterranean.
Do you think it's a coincidence that a Medeteranian diet is so healthy for us (assuming this is a missing link)? It makes sense to me that if we started our branching out in that area that a diet of foods from that area would be what we were designed to eat, and is now found to be a very healthy diet for us.
James Owen for National Geographic News
June 10, 2009
Move over Ida—you're last month's news. There's a new (purported) "missing link" in town.
An 11.9-million-year-old fossil ape species with an unusually flat, "surprisingly human" face has been found in Spain. The discovery suggests humans' ape ancestors split from primitive apes in Europe, not Africa—the so-called cradle of humanity—a new study says.
The species, Anoiapithecus brevirostris, may also represent the last known common ancestor of humans and living great apes—including orangutans, gorillas, and chimpanzees—researchers say.
"With this fossil, our opinion is that the origin of our family very probably took place in the Mediterranean region," said study leader Salvador Moyà-Solà of the Catalan Institute of Paleontology in Barcelona.
"Surprisingly Human"
Unearthed at a fossil-rich site near Barcelona in 2004, the fragmented skull remains suggest a species with human-like facial features, Moyà-Solà said.
But a familiar face in and of itself doesn't mean the fossil "has any special specific relationship with modern hominds"—humans and the great apes—the paleontologist added.
Rather, the human-like face is evidence of great diversity among ape species in the Mediterranean region 12 million years ago, he said.
Missing Link?
Resembling both primitive ape species and our early ancestors, Anoiapithecus could be called a missing link.
The ape's wide nose and long palate, for example, resemble those of the ancient apes from which great apes and humans arose, the study says.
But Anoiapithecus' thickly enameled teeth and robust jaw are like those of primitive Kenyapithecus fossil apes, which lived in both Africa and Europe, according to the team.
Kenyapithecus species have been proposed as common ancestors of humans and great apes.
Until now, however, there hasn't been a fossil linking Kenyapithecus to later apes thought to have evolved into more direct human ancestors, according to the study, published last week in the journal Proceedings of the National Academy of Sciences.
The Spanish ape suggests this key evolutionary transition occurred after Kenyapithecus arrived in Europe from Africa some 15 million years ago—likely crossing over before the Mediterranean Sea formed, separating Africa from Europe—Moyà-Solà said.
"The 'folks' that migrated from Africa to the Mediterranean area were in fact completely primitive, without the [hominid] features that identify the members of our family," he said.
"The ancestors of gorillas, chimps, and humans then went back to Africa close to some nine million years ago."
There, they would give rise to the first humans, the thinking goes.
European Interlude
The new study isn't the first to hint at a European origin for hominids.
A similar theory has been advanced, for instance, based on 10- to 13-million-year-old fossils of the chimplike Dryopithecus group from France, Hungary, and Spain.
Anthropologist David Begun of the University of Toronto believes the evolution of African apes can be traced to Dryopithecus species that had migrated from Africa to Europe during the pre-Mediterranean Sea period.
"The new Spanish fossils do indeed support that hypothesis," said Begun, who was not involved in the new study and whose work has been partially funded by the National Geographic Society's Committee for Research and Exploration. (The National Geographic Society owns National Geographic News.)
However Begun "does not see any compelling evidence" linking Kenyapithecus with the newfound Spanish species.
"Frankly, [the new species] does not look like Kenyapithecus to me," he added.
Moyà-Solà, the study leader, doesn't rule out the possibility that each of the great ape species evolved independently from different Kenyapithecus species.
And it's possible that Africa could yet yield a species that, like the new Spanish ape, bridges the gap between early human ancestors and more primitive apes, he admitted.
"It's impossible to test our hypothesis [as of yet], because the fossil record in Africa from this period is very poor," Moyà-Solà said. "We need more and better fossils from Africa."
To that end, he said, the team's next major scientific stop will be somewhere south of the Mediterranean.
Do you think it's a coincidence that a Medeteranian diet is so healthy for us (assuming this is a missing link)? It makes sense to me that if we started our branching out in that area that a diet of foods from that area would be what we were designed to eat, and is now found to be a very healthy diet for us.
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