Is Beauty More Rewarding for Men?
The bulk of contemporary research supports the conclusion that men value beauty in potential long-term partners more than women do. One potential explanation for this sex difference is that men find beauty more rewarding than do women. Several studies have explored the activity in the brain’s reward circuitry when people view beautiful faces. Jasmin Cloutier and colleagues  are the first to report finding evidence of sex differences in this circuitry in response to attractive faces (Fig 1). They found that men showed more activity in the medial orbital frontal cortex (mOFC) than did women.
Figure 1. Error bars show standard error of the mean. The interaction of attractiveness and sex was significant: F(1, 46) = 4.54, p < .05].
Multiple studies have clearly connected the mOFC with reward and this study shows a significant sex difference in mOFC response to attractive faces. The tendency for many will be to interpret the study as showing that men find beauty more intrinsically rewarding than women. The authors caution against drawing this conclusion too quickly. As they point out, it is premature to conclude that men find beauty more rewarding. We do not yet know precisely what role the mOFC plays in the reward circuitry. For example, Kim et.al. (2007) found evidence that the mOFC may be involved in a slower and more accurate deliberative decision-making system that is appended to the more automatic processing done in the nucleus accumbens (NAC) – a part of the reward system that did not show sex differences in Cloutier’s study.
It may be that while men and women were given the same instructions in this study: ‘Using a 1-4 scale, rate faces on how attractive they are.’ they may actually have been performing different activities. Women may have been responding automatically or aesthetically. Men, in addition, may have been attempting to evaluate who to approach, or who might be more receptive, etc. Until we have a clearer understanding of the mOFC’s role in this sort of task, we cannot be sure about how to understand this difference.
There is one methodological issue that I have not been able to evaluate from the article. The facial stimuli used in this study displayed either a neutral expression or a slight smile and the researchers do report equating the faces. As a technical point, I am curious about the exact nature of the equating. Since faces with slight smiles have been shown to elicit increased activity in the mOFC (O’Doherty et.al., 2003) it is important to know that the ratio of neutral to smiling expressions was identical in the photographs of the men and women used as stimuli.
This is a study worth reading – and one to track in RSS feeds and citation indexes!
Cloutier, J, Heatherton, T.F., Whalen, P.J., & Kelley, W.M. (2008). Are Attractive People Rewarding? Sex Differences in the Neural Substrates of Facial Attractiveness. Journal of Cognitive Neuroscience 20:6, pp. 941–951.
Kim, H., Adolphs, R., John P. O’Doherty, J.P., & Shimojo, S. (2007). Temporal isolation of neural processes underlying face preference decisions. Proceedings of the National Academy of Sciences 104:46, pp. 18253–18258.
O’Doherty, J., Winston, J., Critchley, H., Perrett, D., Burt, D.M. & Dolan, R.J. (2003). Beauty in a smile: the role of medial orbitofrontal cortex in facial attractiveness. Neuropsychologia 41(2):147-55.