Editor’s note: Erica Carranza, Ph.D., is VP of consumer psychology at Boston-based market research firm Chadwick Martin Bailey. This is an edited version of a post that originally appeared under the title, “Was a gender-neutral doll the right move for Mattel?” 

Did I ever tell you about my dissertation? Wait, don’t go! I promise it’s interesting.

It was 2002. My advisor and I had been studying gender stereotypes, which we found were still depressingly pervasive. Then, for my dissertation, I examined reactions to men and women who broke the mold. I thought that people would dislike stereotypically masculine (e.g., ambitious) women and feminine (e.g., sensitive) men, but try to hide it – so I measured their emotional reactions using facial EMG.

Facial EMG involves placing pairs of electrodes over muscles that contract when we frown or smile, as shown on the Mona Lisa. (My apologies to any art history majors out there.) People can’t mask the immediate, involuntary emotional reactions that register in their faces. Most of that muscular activity is too fast and too subtle to be captured by human or computer/AI-based facial coding, but EMG captures it well. If you expect people to actively lie about their feelings, facial EMG is the way to go.

What did I find in analyzing literally millions of milliseconds of facial activity? Feminine men elicited warm smiles from women – but were laughed at by other men. And masculine women were universally reviled. Lots of eyebrow furrowing. People didn’t even try to hide it.

Add this to the many other forces that encourage adherence to gender norms – like the manly men and womanly women portrayed in everything from blockbuster movies to local ads – and it’s no shock that kids learn gender roles early. Kids are perceptive. They see stereotypical male and female characters held-up as ideals in toys and on TV, and can easily infer what’s expected of the...