OR, "why men are much greater consumers of pornography than women."
Dr Petra? Dr Petra...? Paging Dr Petra... Too bad she's on vacation, she would certainly have a field day with this news story (and the original research that spawned it):
Why men like to gaze on the female form
By Roger Highfield, Science Editor
Men find photos of the opposite sex much more "rewarding" than women, new research claims today.
According to the study men take the same pleasure out of looking at an attractive female form as they do from having a curry or making money whereas women do not take any significant reward from looking at pictures of men.
The survey published in the journal Proceedings of the Royal Society B said that brain scan studies show that "reward centres" are triggered in men when they gaze at a woman's face or body whereas they are not in females. It also shows men are more likely to make an effort to view pictures of the opposite sex and pay out money.
The findings shed light on why men are much greater consumers of pornography than women and why sales of Playboy have always exceeded those of Playgirl, according to Dr Benjamin Hayden at the Centre for Neuroeconomic Studies, Duke University School of Medicine, Durham, North Carolina.
. . .
Yes, the experiment by Hayden and colleagues (2007) actually did use images taken from the HOT or NOT site:
Two databases were generated containing over 2000 male and 2000 female images. All images were downloaded from the Hotornot web site (http://www.hotornot.com) in July 2006. This publicly accessible web site allows anyone to post a photo and receive average attractiveness ratings from the browsing public. We selected images that had only a single central subject with a clearly visible face. We eliminated photos which were blurry or small, photos with animals or displays of wealth, photos in which emotionally salient objects such as guns, snakes or motorcycles were visible, photos with subjects in provocative sexual positions or with nudity and photos in which the subjects appeared to be younger than 18 years old.
We ignored the web site's posted ratings and reassessed attractiveness in a laboratory environment. Eleven males each rated all 2000 female photographs in the female database. Eleven females each rated all 2000 male photographs in the male database. Raters were not used as test subjects in subsequent experiments. Ratings were made on a PC using a program that displayed each photo for 1s and then waited for a rating. Raters could press a button to view each photograph again. The instructions asked raters to rate each image for attractiveness on a scale from 1 to 10.
Note that none of the images were pornographic in nature, but that didn't stop Mr. Highfield from extrapolating the results to purchases of Playboy. The Daily Telegraph article also leads you to believe it's a neuroimaging study, but it's not.
Hayden BY, Parikh PC, Deaner RO, Platt ML. Economic principles motivating social attention in humans. Proc Biol Sci. 2007 May 8; [Epub ahead of print].It won't be long before we see the fMRI version.
We know little about the processes by which we evaluate the opportunity to look at another person. We propose that behavioural economics provides a powerful approach to understanding this basic aspect of social attention. We hypothesized that the decision process culminating in attention to another person follows the same economic principles that govern choices about rewards such as food, drinks and money. Specifically, such rewards are discounted as a function of time, are tradable for other rewards, and reinforce work. Behavioural and neurobiological evidence suggests that looking at other people can also be described as rewarding, but to what extent these economic principles apply to social orienting remains unknown. Here, we show that the opportunity to view pictures of the opposite sex is discounted by delay to viewing, substitutes for money and reinforces work. The reward value of photos of the opposite sex varied with physical attractiveness and was greater in men, suggesting differential utility of acquiring visual information about the opposite sex in men and women. Together, these results demonstrate that choosing whom to look at follows a general set of economic principles, implicating shared neural mechanisms in both social and non-social decision making.
ADDENDUM: for a discussion of this paper by an economist, see purple motes.