We see gender differences everywhere – in the psychology, thoughts and behaviour of men and women. But the inclination to see differences makes us blind to the overwhelming similarities of men and women, and we’re easily fooled into seeing dissimilarities that don’t exist.
This tendency can be seen in the great game we love to play called “spot the gender difference”. The game is so easy it’s even played by prepubescent children as they look into one another’s underpants.
Some differences are real, but some are illusory. But we’re so inclined to believe in the dissimilarities of men and women that we even make them up. Around the world, men and women are artificially distinguished from one another by hairstyles, clothing and body adornments.
Gender differences therefore run all the way from undeniable fact to complete fiction. The question is – which differences seem real but are merely imagined?
The answer to this question is important because our beliefs affect our behaviour; the judgements and limits imposed on men and women based on beliefs about differences are real, even if the presumed gender differences are not.
So, what evidence would justify a claim that a difference is real? Science struggles to clarify the situation.
Scientists are looking for gender differences in an untold number of medical and other scientific studies. A search on “gender difference” in Google Scholar since 2012, for instance, returns about 30,000 articles. What’s missing from this list are the untold number of studies where no difference was found because these are not usually published.
Science tends to rely on “statistical significance” to separate real from fictional difference, but simplistic reliance on this arbitrary rule is misleading. If 100 studies examine for a gender difference where there is none, about five (5%) can be expected to return a “statistically significant” difference. This is the false alarm rate or Type I error in statistician-speak.
If Google Scholar reports 30,000 statistically significant differences, our confidence would be seriously undermined if these effects were derived from 600,000 tests for gender differences that otherwise returned no significant results. That is, the significant results are most likely false alarms.
Which gender differences then, are false alarms? It’s hard to say for any single study.
A recent study claims that women’s memories are more affected by stressful news stories than men’s. It was widely reported, but what assurance is there that it is not a false alarm?
Here’s another example - many people believe that women are better at multitasking than men. But at least some research suggests the evidence is more mixed. One study even shows that men are better than women some of the time, and otherwise, there is no difference.
To add to the problem, gender differences are more nuanced than simplistic and sometimes mistaken interpretations of research will allow. While gender is, for the most part, a categorical difference - you are either male or female – many related variables such as height, are more graded.
That is, we find a mean-difference between men and women, and interpret that as a categorical difference. Men are taller than women, but the rule is far from universal; there are many exceptions. On many dimensions that we might measure, the distributions of men and women overlap considerably. There may be a difference in degree (a mean-difference), but the difference is not categorical.
That men and women are more similar than distinct was shown in some recent research. Examining 122 psychological traits including sexual attitudes, behaviours, intimacy and interpersonal orientation in 13 studies comprising over 13,000 individuals, the researchers found that women and men were more similar than distinct from one another.
Even on gender-related dispositions such as masculinity-femininity, inclination toward science, care orientation and fear of success, men and women were found to be more similar than distinctive.
It is claimed that humans and chimpanzees share 96% of their genomic content, despite the many obvious differences between our species. But when looking at the two sexes of Homo sapiens, both with 23 pairs of chromosomes, we choose to focus on just one pair to underscore arguments about gender differences.
Under the spotlight, differences can appear bigger than they are, and can contribute to sexism. So why do we see difference where there is none? We see what we believe. We look for and find evidence supporting what we believe while ignoring contradictory evidence. This is called confirmation bias and it affects us all.
Yes, there are differences between male and female, as we saw when we were very young. But whether all the differences we have marked out since are real is less certain. And while they may make for entertaining bestsellers, such books merely reinforce popular but often false stereotypes.
At best, the public and the scientific community are being misguided by the unchecked reporting of gender differences. At worst, those with an agenda related to gender differences – be they male or female – can cherry-pick studies to support their case.
Correction: One figure in this article has been amended. The original said 20 was 5% of 100. That was obviously incorrect. Thanks to the reader below for pointing it out.