Over the last year or so, I feel like I’ve been playing a game of whack-a-mole with research studies that deny biological sex differences. Yet another study came out last week, in the journal NeuroImage, suggesting that male and female brains are more similar than previously thought. The researchers found that the amygdala, which is involved in emotional processing and has been shown to be sexually dimorphic (or different between the sexes), was roughly 10% larger in men, but after accounting for the fact that men’s bodies are, on average, larger than women’s, this difference in size was no longer deemed statistically relevant.

However, we don’t actually know that a person’s body size has any bearing on the size of this part of the brain. It’s quite possible that a larger amygdala in men is reflective of genuine sex differences in, say, function. And even if there were no differences in the volume of the amygdala, this doesn’t mean there are no differences at all between men and women when it comes to neuroanatomy. For example, the third interstitial nucleus of the anterior hypothalamus, a tiny part of the brain responsible for regulating sexual behavior, has similarly been shown to be sexually dimorphic, as it is consistently larger in men than women.

As well, a lack of differences in brain structure doesn’t rule out differences in functional activation. Indeed, fMRI studies have shown differences between men and women in the amygdala when looking at visual sexual stimuli (also known as porn).

I’ve previously discussed how science on the topic of biological sex differences is currently being molded to fit an ideological framework, and that pretending men and women are identical isn’t scientifically accurate or necessary in order for us to reach gender equality.

Four academic papers published last year fought back against this trend. Of these rebuttals, one team of sex researchers, led by Dr. Marco Del Giudice at the University of New Mexico, ran new analyses on the exact same brain data from the study that suggested you can’t tell male and female brains apart, and was able to correctly determine a given brain’s sex 69 to 77 percent of the time. That’s much higher than what would be expected if the brains were indeed more alike than different.

A movement that prides itself on being progressive and inclusive cannot be allowed to stifle and exclude ideas it deems a threat, especially when doing so carries a cost to our wellbeing. Biological sex isn’t obsolete, seeing as how it informs non-trivial things like our physical and psychological health. For example, heart disease is more common in men and stroke is more common in women.

And from a psychological perspective, men are two to five times more likely to be diagnosed with autism spectrum disorder than women, due to what’s been called the “extreme male brain”.

In addition to the denial of science, what I also find concerning is the way in which this debate is unfolding. Disagreements are important because they encourage you to consider, even for a moment, a perspective that’s different from your own. It’s through hashing it out that progress is made and even if you both still disagree, you move forward with a greater understanding of their position and your own.

Instead, we have reached a point of not being able to speak about this topic without people fanatically throwing around the “sexist” and “bigot” labels before promptly burying their heads in the sand. And in response to my last column on this subject, the “no sex differences” defenders have now changed their tune, saying they’ve never claimed such a thing. As much as the word gaslighting was overused in 2016, that’s exactly what this is, and it’s tiresome.

If you want to pick apart a study badly enough, you can find a way to. If you want to prop up one that was poorly done but backs your claims, you can easily do that, too. Many of the loudest voices, who have no training in neuroscience or–even better–know nothing about sexology, will state their claims and because these opinions have been deemed palatable and safe, they will generally be accepted at face value.

And because the political climate has become too hostile for most scientific experts to say these things aloud, the public discourse has become heavily skewed. I regularly get emails and tweets from people saying how relieved they are, because they thought they were the only one who felt this way and it was making them feel crazy. Having to censor your thoughts will do that to you. They also ask me what they should do.

I say, speak out. Every time one of these studies or misinformed think pieces comes out, I tell people what I really think about it. Engage the people around you in discussion, especially those who disagree. When challenged, people following ideas out of blind faith can’t—and won’t be willing to—debate them with you. But over time, this is how fundamental beliefs without ground are shaken.


Debra W. Soh is a sex writer and sexual neuroscientist at York University in Toronto. She has written for Harper’s, The Wall Street Journal, Scientific American, The Los Angeles Times, The Globe and Mail and many others. Follow her on Twitter: @debra_soh.