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:
The hot-headed “macho man”, who acts first and thinks later, has long been popular in movies. Now there’s psychological evidence to support it. A new study in the Psychological Science finds that a short-term rise in testosterone – as might occur when in the presence of an attractive potential mate, or during competition – shifts the way men think, encouraging them to rely on quick, intuitive, and generally less accurate, judgements, rather than engaging in careful, more deliberate thought.
Most brain imaging studies involving transgender people or people with gender dysphoria have focused on whether their brains look more like what’s typical for the gender they identify with, rather than the gender they were assigned at birth based on their biological sex. For example, whether trans men have “masculine” brains, and trans women have more “feminine” brains.
The results have been mixed and if anything point towards trans people having brains with distinctfeatures that are neither stereotypically male or female.
A new study in Brain Imaging and Behaviour adds to this trend, showing that trans men have unusual patterns of connectivity in brain networks involved in processing of the self, as compared with male and female controls. “The present data do not support the hypothesis that sexual differentiation of the brain of individuals with gender dysphoria is in the opposite direction as their sex assigned at birth,” the researchers said, adding that the unusual connectivity patterns they found in trans men “was detected in comparison with both male and female controls, and there were no differences between the control groups”.
In a ranking of genuinely important YouTube videos to have gone viral, this one (see above) from 2014 places high: it shows over 100 instances of harassment endured by a woman wearing a hidden camera as she walked around New York City for ten hours, including comments, stares, winks and whistles.
The video was posted in 2014 by the domestic violence activist group Hollaback! to highlight the prevalence of this kind of behaviour. As individual testimony, it was powerful. But, critics could argue, it was just one woman, on just one day. This is an argument they cannot use about the results of a new study, published in the British Journal of Social Psychology, which the researchers, led by Elise Holland at the University of Melbourne in Australia, believe is the first to capture just how common sexual harassment and “objectification” is in the daily lives of young women – and to show the possible impact on how women think about themselves.
A team of US researchers led by Lara Stemple at the UCLA School of Law has analysed data from several large federal crime victimisation surveys and they say their findings show that sexual offences by women against male and female victims are surprisingly common. Writing in Aggression and Violent Behaviour the researchers stress that they are in no way intending to minimise the human cost of sexual violence perpetrated by men. But they say their results are “sufficiently robust so as to compel a rethinking of long-held stereotypes about sexual victimisation and gender”.
The experiences of people who’ve been through a gender transition have been studied and analysed by psychologists – showing, for example, improved psychological wellbeing and self-esteem after hormone treatment. But when it comes to their partners, there’s been much less research. According to a new study in the Journal of Social and Personal Relationships, though, they often go through a kind of life transition of their own, and while there are certainly challenges, there are often positive changes, too.
If the courts wanted to know if a suspected sex offender was attracted to children, they could ask him or her, or they could ask experts to measure signs of the suspect’s sexual arousal while he or she looked at different images. But a devious suspect would surely lie about their interests, and they could distract themselves to cheat the physical test.
Brain scans offer an alternative strategy: research shows that when we look at images that we find sexually attractive, our brains show distinct patterns of activation. But of course, the same issues of cheating and deliberate distraction could apply.
Unless, that is, you could somehow prevent the suspect from knowing what images they were looking at, by using subliminal stimuli that can’t be seen at a conscious level. Then you could see how their brain responds to different types of image without the suspect even knowing what they were looking at.
This is the essence of a strategy tested in a new paper in Consciousness and Cognition. Martina Wernicke at Asklepios Forensic Psychiatric Hospital of Gottingen and her colleagues have provided a partial proof of principle that it might one day be possible to use subliminally presented images in a brain scanner to provide a fraud-proof test of a person’s sexual interests. It’s a potentially important break-through for crime prevention – given that deviant sexual interest is one of the strongest predictors of future offences – but it also raises important ethical questions.
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.
An impressive amount of research has linked frequency of sex with greater happiness. One study even put a monetary estimate on it. They said that the happiness spurt from having sex once a week compared with monthly is similar to the boost you’d get from earning an extra $50,000 a year (though for anything more frequent than weekly sex, the benefits seemed to tail off).
Asking if and why more sex makes us happier may sound like asking the blindingly obvious, but of course a lot of pleasurable activities don’t have long-term emotional benefits; it’s also tricky to rule out the simple alternative possibility that we’re more likely to have sex if we’re happy.
In a series of studies in Personality and Social Psychology Bulletin, psychologists in Switzerland and Canada have looked beyond the immediate bliss that sex can bring, and they say that the main reason that more sex seems to contribute to greater long-term happiness is because of all the cuddling (and other expressions of affection) that’s involved, both at the time, and for hours afterwards.
In Talking It Over, Julian Barnes writes that “Love is just a system for getting someone to call you darling after sex”; this new research suggests that sex is a system for getting someone you love to call you darling, and to give you a big cuddle.
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.