Saturday, June 27, 2009

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.
Adapted from materials provided by Wake Forest University.

Friday, June 19, 2009

Some Video Games Can Make Children Kinder And More Likely To Help

ScienceDaily (June 18, 2009) — Some video games can make children kinder and more likely to help—not hurt—other people.
That's the conclusion of new research published in the June 2009 issue of Personality and Social Psychology Bulletin.
The article presents the findings of three separate studies, conducted in different countries with different age groups, and using different scientific approaches. All the studies find that playing games with prosocial content causes players to be more helpful to others after the game is over.
The report is co-authored by a consortium of researchers from the United States, Japan, Singapore and Malaysia.
"Dozens of studies have documented a relationship between violent video games and aggressive behaviors," said lead author Douglas Gentile, an Iowa State University psychologist. "But this is one of the first that has documented the positive effects of playing prosocial games."
Prosocial video games involve characters who help and support each other in nonviolent ways.
"These studies show the same kind of impact on three different age groups from three very different cultures," said Brad Bushman, a University of Michigan co-author of the report. "In addition, the studies use different analytic approaches—correlational, longitudinal and experimental. The resulting triangulation of evidence provides the strongest possible proof that the findings are both valid and generalizable."
"These studies document that children and adolescents learn from practicing behaviors in games," said Rowell Huesmann, a U-M co-author of the report.
One study examined the link between video game habits and prosocial behavior among 727 secondary students in Singapore, with a mean age of 13. Students listed their favorite games and rated how often game characters helped, hurt or killed other characters. They also answered questions about how likely they were to spend time and money helping people in need, to cooperate with others and share their belongings, and to react aggressively in various situations.
As in numerous other studies, the researchers found a strong correlation between playing violent video games and hurting others. But the study also found a strong correlation between playing prosocial games and helping others.
The second study analyzed the long-term connection between video game habits and prosocial behavior in nearly 2,000 Japanese children ages 10 to 16. Participants completed a survey about their exposure to prosocial video games, and rated how often they had helped other people in the last month. Three to four months later, they were surveyed again, and researchers found a significant connection between exposure to prosocial games and helpful behavior months later.
"This suggests there is an upward spiral of prosocial gaming and helpful behavior, in contrast to the downward spiral that occurs with violent video gaming and aggressive behavior," said Bushman, a professor of communications and psychology and a research professor at the U-M Institute for Social Research (ISR).
For the third study, the researchers carried out an experiment with 161 U.S. college students, with a mean age of 19. After playing either a prosocial, violent, or neutral game, participants were asked to assign puzzles to a randomly selected partner. They could choose from puzzles that were easy, medium or hard to complete. Their partner could win $10 if they solved all the puzzles. Those who played a prosocial game were considerably more helpful than others, assigning more easy puzzles to their partners. And those who had played violent games were significantly more likely to assign the hardest puzzles.
"Taken together, these findings make it clear that playing video games is not in itself good or bad for children," Bushman said."The type of content in the game has a bigger impact than the overall amount of time spent playing."
Adapted from materials provided by University of Michigan.

Friday, June 5, 2009

Be Your Best Friend If You'll Be Mine: Alliance Hypothesis For Human Friendship


ScienceDaily (June 5, 2009) — University of Pennsylvania psychologists studying the cognitive mechanisms behind human friendship have determined that how you rank your best friends is closely related to how you think your friends rank you. The results are consistent with a new theory called the Alliance Hypothesis for Human Friendship, distinct from traditional explanations for human friendship that focused on wealth, popularity or similarity.
The study, performed by Penn cognitive psychologists Peter DeScioli and Robert Kurzban, has demonstrated that human friendship is caused, in part, by cognitive mechanisms aimed at creating a ready-made support group for potential conflicts. People call on friends for help in a variety of disputes, ranging from trivial arguments to violent fights. This study suggests that people have specialized decision processes that prioritize those individuals who tend to be most helpful in conflicts, those with fewer stronger commitments to others.
Researchers performed question-and-answer studies in which participants ranked their closest friends in a number of ways, including, for example, the benefits they receive from the friendship, the number of secrets shared and how long the friendship has been ongoing. Each time, whether participants were an online community, random passersby on a metropolitan street or undergraduate students in a laboratory, friendship rankings were most strongly correlated with individuals' own perceived rank among their partners' other friends.
"Historically, the main theory has been that humans build friendships in order to trade in goods and services," DeScioli, lead author, said. "The problem we focused on was that friendship involves more than exchange. People want friends who care about them and do not give just to get something back in return. We thought that theories about alliances might help explain why friends are primarily concerned with each others' needs rather than the benefits they can get in return for helping."
Traditional evolutionary approaches to explain human friendship apply the Theory of Reciprocal Altruism: Friends function as exchange partners; however, a wealth of empirical evidence from social psychology is inconsistent with the theory. For example, in prior studies it was shown that people do not keep regular tabs on the benefits given and received in close relationships. Also, people seem to help friends even when they are unlikely to be capable of repayment. For cognitive psychologists, it is unclear what humans and their complex brains are up to in creating these relationships.
The new Penn theory has origins in models of alliance building between nations, which prepare for conflict in advance but may not expect anything in return immediately.
"Friendships are about alliances," Kurzban, an associate professor, said. "We live in a world where conflict can arise and allies must be in position beforehand. This new hypothesis takes into account how we value those alliances. In a way, one of the main predictors of friendship is the value of the alliance. The value of an ally, or friend, drops with every additional alliance they must make, so the best alliance is one in which your ally ranks you above everyone else as well."
In short, the hypothesis is much more optimistic about the reasons for friendship than existing theories which point toward popularity, wealth and proximity as reasons for friendship.
"In this hypothesis," Kurzban said, "it's not what you can do for me, it's how much you like me. In this manner even the weakest nations, for example, or the least popular kid at the party with nary an alliance in the room is set up to be paired with someone looking for a friend."
More darkly, the new model also serves as an explanation for some petty human behaviors not explained by traditional friendship theories. For example, the Alliance Hypothesis explains why people are extremely concerned with comparisons to others in their social circle. It also explains how jealousies and aggression can erupt among groups of friends as alliances are shifted and maintained.
If the Alliance Hypothesis for Human Friendship is correct, then theories about alliances from game theory and international relations might help us better understand friendship. These theories suggest that people in conflict would benefit strategically from ranking their friends, hiding their friend-rankings and ranking friends according to their own position in partners' rankings. To employ these tactics in their friendships, people need to gather and store information about their friends' other friendships. That is, they have to readily understand the social world not only from their own perspective but also from the perspectives of their friends.
Although friendship is a core element of human social life, its evolved functions have been difficult to understand. Human friendship occurs among individuals who are neither relatives nor mates, so the function of this cooperative behavior is not as clear as when reproduction or genetic relatives are involved. Similar relationships have been observed in non-human species -- hyenas use partners to gain access to carcasses and male dolphins employ "wingmen" to attain females for mating — and considerable progress has been made in understanding these non-human relationships. But the functions of human friendship have been more elusive.
The study, appearing in the current issue of the online journal Public Library of Science One, was conducted by DeScioli and Kurzban of the Department of Psychology in the School of Arts and Sciences at Penn.
It was supported by a fellowship from the International Foundation for Research in Experimental Economics.
Adapted from materials provided by University of Pennsylvania, via EurekAlert!, a service of AAAS.

Basket Weaving May Have Taught Humans To Count


ScienceDaily (June 3, 2009) — Did animals teach us one of the oldest forms of human technology? Did this technology contribute to our ability to count? These are just two of the themes due to be explored at a conference on basketry at the University of East Anglia.
The event, which takes place today and tomorrow (June 5-6), is part of Beyond the Basket, a major new research project led by the university exploring the development and use of basketry in human culture over 10,000 years.
Basketry has been practised for millennia and ranges from mats for sitting on, containers and traps for hunting, to fencing and barriers for animals or land, partitions and walls - all of which have been central to culture.
Beyond the Basket is a two-and-a-half year project funded by the Arts and Humanities Research Council as part of its Beyond Text programme. The research will explore the role of basketry in human culture and focus on various parts of the world, both in the past and present, from Europe to Amazonia, central Africa and Papua New Guinea.
The aim is to identify the mechanical traditions of making and the ways in which basketry is implicated in wider patterns of understanding, for example the order of society or the design of the universe. It will also show the impact of woven forms on other media, such as pottery, painting, and stone sculpture and architecture, and look at the future of basketry and the solutions it could offer to current issues, whether technical or social.
Project leader Sandy Heslop, of the School of World Art and Museology at UEA, said: “Basketry is a worldwide technology and is the interaction between human ingenuity and the environment. It tends to make use of, and therefore has to be adapted to, local conditions in terms of resources and environment.
“Without basketry there would be no civilisations. You can’t bring thousands of people together unless you can supply them, you can’t bring in supplies to feed populations without containers. In the early days of civilisations these containers were basketry.
“We may think of baskets as humble, but other people and cultures don’t. They have been used for storage, for important religious and ceremonial processes, even for bodies in the form of coffins.”
It is about 10,000 years ago that evidence for basketry starts to appear in North America, Asia, Europe and the Middle East. Today its uses and influences are still seen, from the bamboo scaffolding often used in Asia, to contemporary architecture, for example the ‘Boiler Suit’ - the name given to the ‘woven’ steel tiles encasing the boiler room at Guy’s Hospital in London.
Mr Heslop said: “Beyond its practical uses, basketry has arguably been even more influential on our lives, since it relies on the relationship of number, pattern and structure. It therefore provides a model for disciplines such as mathematics and engineering and for the organisation of social and political life.
“Given the range of uses of basketry the associations of the technology are very varied. Some are aggressive, others protective, some help create social hierarchies others are recreational.”
The conference, Beyond the Basket: Construction, Order and Understanding, will look at various themes including: design and production, environmental issues, commercial and historical perspectives, weaving in architecture, and the mathematics of basketry, as well as more anthropological and archaeological topics. Among the speakers will be experts from North and South America, as well as the UK.
Beyond the Basket will culminate in an exhibition and accompanying book in 2011. The exhibition will include ancient material recovered by excavation as well as more recent examples of basketry from around the world and will enable people to experience basketry directly.
For further information about Beyond the Basket and to view images visit
Adapted from materials provided by University of East Anglia, via AlphaGalileo.

High Population Density Triggers Cultural Explosions


ScienceDaily (June 5, 2009) — Increasing population density, rather than boosts in human brain power, appears to have catalysed the emergence of modern human behaviour, according to a new study by UCL (University College London) scientists published in the journal Science.
High population density leads to greater exchange of ideas and skills and prevents the loss of new innovations. It is this skill maintenance, combined with a greater probability of useful innovations, that led to modern human behaviour appearing at different times in different parts of the world.
In the study, the UCL team found that complex skills learnt across generations can only be maintained when there is a critical level of interaction between people. Using computer simulations of social learning, they showed that high and low-skilled groups could coexist over long periods of time and that the degree of skill they maintained depended on local population density or the degree of migration between them. Using genetic estimates of population size in the past, the team went on to show that density was similar in sub-Saharan Africa, Europe and the Middle-East when modern behaviour first appeared in each of these regions. The paper also points to evidence that population density would have dropped for climatic reasons at the time when modern human behaviour temporarily disappeared in sub-Saharan Africa.
Adam Powell, AHRC Centre for the Evolution of Cultural Diversity, says: "Our paper proposes a new model for why modern human behaviour started at different times in different regions of the world, why it disappeared in some places before coming back, and why in all cases it occurred more than 100,000 years after modern humans first appeared.
"By modern human behaviour, we mean a radical jump in technological and cultural complexity, which makes our species unique. This includes symbolic behavior, such as abstract and realistic art, and body decoration using threaded shell beads, ochre or tattoo kits; musical instruments; bone, antler and ivory artefacts; stone blades; and more sophisticated hunting and trapping technology, like bows, boomerangs and nets.
Professor Stephen Shennan, UCL Institute of Archaeology, says: "Modern humans have been around for at least 160,000 to 200,000 years but there is no archaeological evidence of any technology beyond basic stone tools until around 90,000 years ago. In Europe and western Asia this advanced technology and behaviour explodes around 45,000 years ago when humans arrive there, but doesn't appear in eastern and southern Asia and Australia until much later, despite a human presence. In sub-Saharan Africa the situation is more complex. Many of the features of modern human behaviour – including the first abstract art – are found some 90,000 years ago but then seem to disappear around 65,000 years ago, before re-emerging some 40,000 years ago.
"Scientists have offered many suggestions as to why these cultural explosions occurred where and when they did, including new mutations leading to better brains, advances in language, and expansions into new environments that required new technologies to survive. The problem is that none of these explanations can fully account for the appearance of modern human behaviour at different times in different places, or its temporary disappearance in sub-Saharan Africa."
Dr Mark Thomas, UCL Genetics, Evolution and Environment, says: "When we think of how we came to be the sophisticated creatures we are, we often imagine some sudden critical change, a bit like when the black monolith appears in the film 2001: A Space Odyssey. In reality, there is no evidence of a big change in our biological makeup when we started behaving in an intelligent way. Our model can explain this even if our mental capacities are the same today as they were when we first originated as a species some 200,000 years ago.
"Ironically, our finding that successful innovation depends less on how smart you are than how connected you are seems as relevant today as it was 90,000 years ago."
Journal reference:
Adam Powell, Stephen Shennan, and Mark G. Thomas. Late Pleistocene Demography and the Appearance of Modern Human Behavior. Science, 2009; 324 (5932): 1298 DOI: 10.1126/science.1170165
Adapted from materials provided by University College London, via EurekAlert!, a service of AAAS.