The link between attractiveness and facial symmetry seems to hold across both black and white faces, but also in non-human primates, according to a study just published in the open-access science journal PLoS One.
One of the most striking studies in sex and symmetry research isn’t mentioned, however. A 1995 study found that the likelihood of female orgasm during sex was related to the extent of bodily symmetry in the male partner.
The study was led by biologist Randy Thornhill and recruited 86 young couples who completed a number of relationship questionnaires, including one on how often the female partner orgasmed during sex. The males then had their bodies measured and assessed for how much one side differed compared to the other – a measure of bodily asymmetry.
In the final analysis neither the male’s age, wealth, social skills, physical attractiveness or relationship style predicted the frequency of female orgasm. Only male bodily symmetry was statistically associated with the chance of the women climaxing during sex.
The researchers thought that maybe women who have more orgasms, or who are just more sexual, simply get the more symmetrical (maybe hotter) guys. But when they looked at frequency of orgasm outside copulation (such as during oral sex or masturbation), the relationship to male symmetry disappeared, suggesting that this wasn’t the case.
This study, and the new study published in PLoS One, also suggested that symmetry was associated with more masculine features generally – a bigger body in the orgasm study, and a more typically male face in the PLoS research.
The evolutionary explanation suggested by the authors is that female orgasm during copulation may make pregnancy more likely, so it’s an adaptive strategy to increase fertility when making love to males with genes more likely to lead to healthy children.
How orgasm increases with body symmetry is not clearly understood, though. The authors speculate that female perception of a highly symmetrical male might psychologically prime sexual arousal, but the mechanism is left largely to guesswork.
Link to PLoS One study on attractiveness and symmetry (via Anthro).
Link to abstract of orgasm and symmetry study.
Mind Hacks 
This is an example where the word “authority” has full sense.The authors of the study are the top-world authorities in face research and i believe whatever they say.
But according to their work too, symmetry is just one feature from the many present in the multimodal trasmitting device relevant for social intercourse that is the face. Other traits are secondary sexual characteritics and the physical conditions of both the observer of the face and the person with the concrete face, ussually disociable from symmetry.
This is one of those studies that people inevitably read and then think, I wonder if that applies to me?
I’d like to point out that, although this study is most likely accurate and has been carefully controlled, there are many, many different factors which affect female pleasure and orgasm other than symmetry (e.g. hormonal cycle, menopause, depression, anti-depressant use, alcohol (yes! get her drunk..) security in relationship etc..)
Also, it is unlikely that many males have had sexual encounters with enough women personally to have a statistically significant sample (those who have had at least 30+ are very lucky! even then I bet they never did their stats properly).
This means that most of us base our experiences of relationships on an Availability Heuristic. So if your partner is not getting as much pleasure as you or she would like, try exploring alternatives, and don’t immediately think that you are not symmetrical enough…..
How can a man measure his symmetry? If he discovers his symmetry is not high enough, what is he supposed to do if his female partner is not satisfied with him for reasons he cannot control?
An open relationship? Maybe talk with your partner about getting her big O with a more attractive (i.e: symmetrical) short term partner? Communications goes a long way.
@Tom Michael
Of course it applies to you, why wouldn’t it?
@Matthew
If you lack body symmetry and cannot sexually satisfy your partner due to it, you could always try sexual therapy for couples. Maybe your partner can learn to imagine herself (or himself) why someone with higher body symmetry? Don’t despair I’m sure there are plenty of “unattractive” (low symmetry) couples that can have a healty sexuality. Otherwise, everyone would look like a model which is clearly not the case, heh. Just check your local Walmart š
I’ve been told that I’m attractive by many people, so maybe I shouldn’t worry so much.
So you’re saying my partner can only be satisfied if she fantasizes about someone else during sex? How is that supposed to make me feel better?
My theory is that symmetry from a heterosexual female’s point of view is a subconscious decision that is a mix of primal thought processes and pheromone detection. They go hand in hand. Another study said that the sexual dimorphism in male’s chins is the only facial denominator when it comes to sexual attraction. Facial symmetry only determines the friendliness factor and does not influence females sexually. If body symmetry is a factor of mental and immune system health then the pheromone signal would be a good means to detect errors in addition to obvious physical defects.
tl;dr
Sex potential = how dominant male face is (chin) and how ideal the immune system signal (pheromones) is