I've never been a big fan of the idea – so beloved by romance novelists – that the eyes are "windows" to the inner person. And when I teach narrative writing I always warn my students that if they must see a person's "soul in his/her eyes" that it had better be due to a major scientific discovery. Otherwise, their grades will be heading south.
So when I saw this headline in the Los Angeles Times, Sexual Orientation: The Eyes Tell All, my first reaction was to (sorry, couldn't resist here) roll my eyes. But as the author was Thomas H. Maugh II – as solid and cautious a science writer as I know – I decided to give it a second look. And it actually turned out to be an interesting story, although, probably not surprisingly, more complicated than the headline might suggest.
The basic premise is this: Scientists have been looking for a relatively unobtrusive way of measuring sexual response or arousal. The standard technologies are fairly, um, invasive and Maugh actually provides a fairly hilarious description (to me) of eager test subjcts volunteering their bodies to this kind of science. But eventually a couple of researchers, Gerulf Rieger and Ritch C. Savin-Williams at Cornell University hit on the idea of measuring pupil dilation in response to arousal. They surveyed and selected 165 men and 160 women and showed them short erotic films, some featuring men and some featuring women. The results were reported in PLoS ONE last week.
The researchers found that men, self-identified as heterosexual on the survey, routinely showed pupil dilation when watching the female-focused films. The opposite held true for gay men. And again for gay women, who responded most intensely to female erotic images. But heterosexual women showed signs of response to both male and female erotic images, much like the response of bisexual men. The latter finding tends to reinforce a long-held idea in gender biology that women can adjust more easily in this regard than men. But, as a short-unbylined piece in Medical Xpress notes, it also adds to understanding of male bisexuality.
Maugh does a very nice job of reviewing these different aspects of the study. Eddie Wrenn of the Daily Mail does, I think, an even better job of putting the story into perspective from the start, focusing the story on "sexual preference" rather than orientation. And Anna North, at Buzzfeed, focused her reporting on the question of bisexuality in particular.
But it won't surprise you to know that the big sell point of this story was the idea that the eyes are "windows" to sexual orientaiton. To whit:
Do Eye Make You Horny, Baby? Pupil dilation key indicator of sexual orientation, say new study, by Christine Roberts at the New York Daily News.
Think You're Gay? It Shows in Your Eyes, According to Study, by Susan Donaldson James at ABC News.
Sexual Orientation: Eyes Reveal Who's Gay & Who's Straight, by Stephanie Pappas of LiveScience (picked up here by Huffington Post Science).
To be fair, you can find reference to the overall sexual preference context in most of these stories; Pappas includes some thoughful quotes on the bisexuality issues. But the emphasis in these stories – and the 50-odd others I turned up – was strong enough, that the magazine, Instinct, wrote the story up this way: "Move over guyliner and tweezers—thanks to a new study out of Cornell University, researchers believe it's possible to accurately identify a person's sexual orientation based on their eyes alone."
Which leads me that cautionary note that you probably saw coming. I don't want to dismiss the Cornell findings or suggest that there's not some solid reasoning, and even scientific history, behind them. The connection between pupil dilation and emotional response is nothing new. In fact, there's quite a good discussion of it in this HowStuffWorks article by Christian Conger that makes a point of citing a 1965 article in Scientific American. Almost everything I read would have been improved by a better sense that this study is, in part, a new twist on some well-established research. And that the earlier research did not transform our sexual understanding to the degree that some of this enthusiastic coverage suggests might happen here.
We need, yes, sorry, more studies to really clarify this and more precision. Are there degrees of dilation that mean different things, for instance? Athough I do love the idea of people in bars or at parties peering into their dates' eyes to check on pupil dilation. – we should be careful about over-selling it. Because we do have a good history here, we know that arousal isn't the only thing that dilates pupils – so do medications, including eye drops, so does standing in darkened room (think bars here), so do some medical conditions, and so do other emotions, such as fear. What we see in a controlled study is often very different from what we see in the messy real world. And there are times when the eyes are no more than a window on an earlier visit to the optometrist.
— Deborah Blum