How Pupils Advertise Attraction
Italian women in the Middle Ages were a step ahead of science. Recognizing the beauty endowed by wide-open pupils, they would dilate their own eyes with belladonna [source: Gowin]. (Incidentally, the word "belladonna" means "beautiful woman" in Italian.) Unfortunately, the plant secreted not only the chemical atropine, which draws back the irises, but also a toxin that would poison them [source: Swaminathan].
Although belladonna wasn't an optimal dilating agent, the come-hither effect of large pupils was a scientifically valid assumption.
In 1965, pupillometry pioneer and psychologist Hess asked men to compare the attractiveness of images of women with average-sized pupils to drawings in which the women's pupil sizes were enhanced. Consistently, men ranked the doe-eyed gazes as prettier, since the subtle ocular opening unconsciously signals sexual attraction on the woman's part [source: Murphy]. In response to attraction, the brain secretes norepinephrine [source: Fisher]. That chemical then flexes the eyeball's dilator muscles [source: Gowin]. Therefore, men may unwittingly read pupil dilation as an advertisement of interest.
Studying women's preferences for male pupil sizes wasn't so predictable, however. Researchers have found that some women prefer men with medium-sized pupils, apparently because they were perceived as not being oversexed and more likely to be dependable partners in raising offspring. But others were drawn to men with large pupils. Those women told the researchers that they had a tendency to get involved with "bad boy" types [source: Murphy].
But there seems to be a common pattern: The more physiologically primed for sex they are, the more males and females both innately keep an eye out for dilated pupils. Given that evolutionary phenomenon, the eyes are less the windows to one's soul than the windows one's bedroom.
More Great Links
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- Caryl, Peter G. "Women's preference for male pupil size: Effects of conception risk, sociosexuality and relationship status." Personality and Individual Differences. March 2009. (Jan. 31, 2012) http://www.sciencedirect.com/science/article/pii/S0191886908004509
- Fisher, Helen E. "Brains Do It: Lust, Attraction, and Attachment." Dana.org. Jan.1, 2000. (Feb. 7, 2018) http://www.dana.org/Cerebrum/Default.aspx?id=39351
- Gowin, Joshua. "Beauty Is in the Eye." Psychology Today. July 08, 2010. (Jan. 31, 2012) http://www.psychologytoday.com/blog/you-illuminated/201007/beauty-is-in-the-eye
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- Murphy, Cheryl. "Learning the Look of Love: In Your Eyes, the Light the Heat." Scientific American. Nov. 01, 2011. (Jan. 31, 2012) http://blogs.scientificamerican.com/guest-blog/2011/11/01/learning-the-look-of-love-in-your-eyes-the-light-the-heat/
- Stern, Robert Morris; Ray, William J.; and Quigley, Karen S. "Psychophysiological Recording." Oxford University Press. 2001. (Jan. 31, 2012) http://books.google.com/books?id=9WmvzrkZdv8C&dq=hess+attraction-dilation+hypothesis&source=gbs_navlinks_s
- Swaminathan, Nikhil. "How did they find the chemical that dilates your pupils?" Scientific American. Feb. 25, 2008. (Jan. 31, 2012) http://www.scientificamerican.com/article.cfm?id=experts-chemical-pupil-dilate
- Tombs, Selena and Silverman, Irwin. "Pupillometry: A sexual selection approach." Evolution and Human Behavior. April 23, 2004. (Feb. 7, 2018) https://pdfs.semanticscholar.org/9ae2/4f1cc3877903694b42992080b6d607fac24c.pdf
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