We have a mostly impressive ability to identify people we know based on the sound of their voice, but prior research has uncovered an intriguing exception – we’re not very good at discerning identity from laughter. Now Nadine Lavan and her colleagues have published research in Evolution and Human Behavior that looks into why this might be and what it says about our evolutionary past.
One year ago today, Donald J Trump, a man with no political or military experience, defied expectations, winning the election to become the 45th president of the United States. Nearly 63 million voted for him, including, and in spite of his reputation for sexism, over half of all white women. In an open-access paper in Evolutionary Studies in Imaginative Culture, Dan McAdams, one of the world’s leading experts in personality psychology, proposes an explanation for Trump’s popular appeal that is grounded in evolutionary psychology, personality theory and the social psychology of leadership.
There are behavioural differences, on average, between the sexes – few would dispute that. Where the debate rages is over how much these differences are the result of social pressures versus being rooted in our biology (the answer often is that there is a complex interaction between the two).
For example, when differences are observed between girls and boys, such as in preferences for play, one possibility is that this is partly or wholly because of the contrasting ways that girls and boys are influenced by their peers, parents and other adults (because of the ideas they have about how the sexes ought to behave). Studying non-human primates allows us to identity sex differences in behavior that can’t be due to human culture and gender beliefs.
Learning more about the biological roots of behavioural sex differences should not be used as an excuse for harmful stereotyping or discrimination, but it can help us better understand our human nature and the part that evolved sex differences play in some of the most important issues that affect our lives, including around diversity, relationships, mental health, crime and education.
“Many sex differences in behavioral development exist in nonhuman primates,” she writes, “despite a comparative lack of sex-biased treatment by mothers and other social partners”. Here is a digested account of five of these behavioural sex differences:
Conscientiousness is a fundamental aspect of human personality, with higher levels associated with all kinds of benefits, from greater academic achievement and relationship stability to living for longer. Yet it’s the only major human personality dimension not to have been widely identified in animals, which poses an evolutionary puzzle – if animals don’t show signs of conscientiousness, where did the human variety come from? But now a major review of hundreds of relevant papers, published in Psychological Bulletin, concludes that in fact, “there are many documented examples of conscientiousness behaviour in other animals”. The work also suggests that there are two main branches to conscientiousness, each associated with an evolutionary drive to solve different types of problems.
While the idea that the lack of women in science and tech is entirely about cultural obstacles is contentious (as demonstratedby the recent Google memo furore), few would argue that social and cultural factors aren’t important. And these social influences may begin early. For example there’s an argument that boys are encouraged to play with toys that are likely to promote skills that will help them in science and maths. Toys aimed at girls, in contrast, are more likely to promote stereotypically feminine skills, such as nurturing.
LEGO, say Megan Fulcher and Amy Hayes, the authors of a new paper in the journal Sex Roles, is a case in point: its marketing is skewed towards boys, especially since the increase in packaged sets, which tend to feature stereotypically masculine items like pirate ships and castles. The result, they argue, is that boys are more attracted to LEGO, girls deterred from it, and that boys get to practice their building skills while girls don’t.
LEGO has heard some of this criticism (and no doubt also seen a gap in the market) and they’ve released girl-friendly packaged sets and product lines, including Friends items with a focus on people and including pink bricks. But Fulcher and Hayes – who very much speak from the nurture perspective on these issues (they fail to cite a single study demonstrating a biological basis for sex differences in toy preference) – fear this could be counterproductive because girlie bricks and sets are likely to promote more stereotypically feminine LEGO play and remind girls of their gender. To find out if their concerns are justified the researchers tested the LEGO building skills and choices of 116 girls and boys (aged 5 to 10) depending on whether they were given boyish LEGO bricks and packages or girlie ones.
To understand the drivers of a psychopathic personality (marked by callousness, disinhibition and superficial charm), it’s worth looking at our closest relatives. Some chimps, like some people, score highly on scales designed to evaluate psychopathic tendencies. And new work in Frontiers in Neuroscience reveals a potentially important genetic contributor to psychopathic traitsin chimps, which could lead to a better understanding of the traits in people.
How far has evolutionary thinking permeated through academia? A survey of more than 600 scholars from 22 disciplines, ranging from psychology and economics through to gender studies, sociology and the humanities, finds that there remain two distinct cultures in the academe, at least regarding views on the principal causes of human behaviour and human culture.
One group, made up of psychologists, economists, philosophers and political scientists believes more strongly in the genetic influences on behaviour, beliefs and culture. The other group, consisting sociologists, non-evolutionary anthropologists, women’s and gender studies scholars and all humanities scholars (except philosophy), believes in the primacy of environmental influences. What’s more, those scholars favouring environmental accounts also tend to be sceptical of the scientific method. The findings are published open-access in the newly launched journal Evolutionary Studies in Imaginative Culture.
You probably won’t be reaching for your violin too quickly but a series of new studies provide compelling evidence that beauty is a kind of “relationship liability”. While more physically attractive people have a clear advantage when it comes to finding partners, the results suggest that their relationships are more likely to breakdown, at least in part because they take greater interest in alternative partners, especially when dissatisfied in their current relationship.
The results add further nuance to our understanding of how physical beauty impacts people’s lives. While good-looking folk seem to enjoy many advantages in life, on average, such as higher pay, more happiness and others assuming they are friendly and intelligent, it seems there are complicating factors: jealousy is one, and this new research, published in Personal Relationships, suggests that less stability in their romantic relationships is another.
Studies show that when heterosexual women look at other women’s bodies, they, just like men, tend to spend a disproportionate amount of time looking at their waists, hips and breasts, as if estimating how much they will appeal to men. This is consistent with “mate selection theory” which argues, among other things, that women have evolved strategies to monitor potential love rivals. However, psychologists are interested in this topic, not only from an evolutionary perspective, but also because women who feel dissatisfied with their bodies, and who are vulnerable to developing eating disorders, may be especially pre-occupied with comparing their body against others, potentially exacerbating their anxieties.
Past research is mixed: some studies suggest women with body dissatisfaction and/or eating disorders pay disproportionate attention to the bodies of thin women, other studies suggest the opposite. A new exploratory paper in Psychological Research says hang on a minute, we don’t actually know much about how healthy, confident women behave when they look at other women, nor whether their attention is influenced by their feelings about their own bodies.
It’s one of the simplest, most evidence-backed pieces of advice you can give to someone who’s looking to attract a partner – wear red. Many studies, most of them involving men rating women’s appearance, have shown that wearing red clothing increases attractiveness and sex appeal. The reasons are thought to be traceable to our evolutionary past – red displays in the animal kingdom also often indicate sexual interest and availability – complemented by the cultural connotations of red with passion and sex.