Can’t Read Minds? Blame The Testosterone.

Wearing your heart on your sleeve is merely an adage, but most people do display their emotions – even if unintentionally – on their faces. Women tend to be better than men at reading other people’s subtle facial cues, especially cues from the eyes. Because of the gender difference in cognitive empathy – the ability to notice and correctly interpret body language – psychobiologistsscientists that study psychology from a biological perspective, or vice versa have hypothesized that testosteronea sex hormone present in much higher levels in males versus females levels could play a role in “mind reading” ability, or lack thereof.

A new study in PNASProceedings of the National Academy of Sciences validates this hypothesis by demonstrating that a dose of testosterone can make women lose some of their cognitive empathy. Researchers recruited 16 young women (age 20-25) to participate in their study. The women were given either a testosterone pill or a placebo, and then tested on their ability to assess emotions based on photographs of eyes. The test the women took is called the Adult Eyes Test, and is available for free from the Autism Research Center at the University of Cambridge. Here’s a sample question (formatting is slightly modified):

testosterone impairs reading facial expressions cognitive empathy

For the correct answer, click here.

Each woman was tested twice – once with placebo and once with real testosterone (in random order; they didn’t have any idea which was which). 75% of the women performed worse on the “mind reading” test after taking testosterone than after taking a placebo. So to a first approximation, an artificial increase in testosterone levels impaired women’s abilities to interpret facial expressions.

But the results aren’t quite that simple. Some women were less affected by the extra testosterone than others, and the researchers had a hunch that this could relate to their exposure to testosterone in the womb. All fetuses are exposed to testosterone while developing, but to different extents. There is a simple way to qualitatively measure fetal testosterone exposure – this parameter is believed to be correlated to the adult ratio of ring finger length to index finger length:

testosterone impairs facial expression reading ability cognitive empathy

Larger ratios of ring finger to index finger lengths correspond to higher fetal testosterone levels. This study showed no difference between the inherent expression-reading ability of women exposed to higher vs. lower doses of testosterone in the womb. However, the women with longer ring fingers (higher fetal testosterone) seemed to be more easily impaired when given a dose of testosterone in pill form.

Thus, this study demonstrated that (1) testosterone administered to women can impair their ability to read facial expressions, and (2) women who experienced more testosterone in the womb are more sensitive to the effects of testosterone administered as adults. Nothing further can be definitively gathered from these results, but they seem to suggest that men’s testosterone levels could be to blame for their increased confusion about what others (especially women!) are thinking/feeling.

Just for fun, here are a few famous hands (source). Remember, longer ring fingers = more “masculine” hands. It’s important to note, however, that gender or perceived masculinity/femininity can’t be predicted merely from this ratio. The ratio is really only relevant when comparing groups of people, with all else being equal.

testosterone impairs facial expression reading ability cognitive empathy

van Honk, J., Schutter, D., Bos, P., Kruijt, A., Lentjes, E., & Baron-Cohen, S. (2011). Testosterone administration impairs cognitive empathy in women depending on second-to-fourth digit ratio Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1011891108

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5 Responses to Can’t Read Minds? Blame The Testosterone.

  1. Wow, I got that look totally wrong. Nice post!

    • Thanks Leigh, yeah it’s tricky!!! Apparently women’s hormonal changes and their mood also have something to do with how well they can read facial expressions at any given time. (They controlled for those things in this study.)

    • Duane says:

      I got it right – and I’m a guy…

      It has been pointed out to me that I’m ‘emotionally intelligent’, guess this is some proof of that…

  2. Edwin Rutsch says:

    My I suggest a further resources to learn more about empathy and compassion.
    The Center for Building a Culture of Empathy
    The Culture of Empathy website is the largest internet portal for resources and information about the values of empathy and compassion. It contains articles, conferences, definitions, experts, history, interviews,  videos, science and much more about empathy and compassion.

    Let’s Find 1 Million People Who Want to Build a Culture of Empathy and Compassion

    Also, we invite you to post a link to your article about empathy to our Empathy Center Facebook page.


  3. Nathan says:

    I’m just not buying these dimorphic differences in skills such as facial recognition. There’s too much bad science in the mix, and contradictory results that I don’t know what to believe.