What explains the relative importance of physical versus mental features in human mate selection? I assume that it is the brain that has put human beings at the top of the food chain (Biped and  opposable thumbs aside).

Darwin's theory of survival of the fittest suggest that the best specimens of a species are those that have the greatest mating privileges. I assume that well developed characteristics, required by that species to ensure survival will will be sought after, not just of one particular group, but the species as a whole. So for lions it strength will be desired, and for elephants size will matter.

For humans, it is the  brain that is our evolutionary marvel. It sets us apart from all other species.  I think human physical prowess is somewhat redundant when it comes to our survival and progress. 

Many highly intelligent people are still regarded as social misfits, nerds and geeks. The high school football team and cheer leaders are still very popular.
Sports stadiums are filled and televised, and the regular chess clubs are not.
This seems a bit like a limiting mechanism, where we are not smart enough to overcome our base natures and so the truly, evolutionary, superior specimens are downgraded, whilst the redundant brawny types that appeals to the apes, are still highly sought after.


What is the relative importance of physical versus mental features in human mate selection?
Do mental features receive relative little weighting?
What is the evolutionary psychology argument for the relative importance of physical versus mental features in mate selection?
In my experience, physical trumps all.  Even if you're blind, there is still smell.  I saw a show (The Science of Sex Appeal) which documented an experiment where a group of men wore t-shirts while getting sweaty on treadmills.  Once the garments were nice n nasty, they put them in jars and had women rate how turned on or off they were by smelling each jar.  It turned out that at least one of the women had a brother in the experiment and she rated his smell especially off-putting.  This led researchers to conclude that smell is important in avoiding inbreeding.  If someone's immune system is similar to yours, they will smell similar to you and you won't like it.  Similar immunities kill similar bacteria, resulting in similar smells.
We also look for things that indicate genetic health.  Nice teeth is probably the biggest.  Do you have nice eyes?  Without teeth and good vision, its hard to survive in the wild.  The caveat here seems to be access to healthcare.  Of course, we can fake our genetic flaws with contact lenses and dental work, but even wearing glasses (which is not an advantage) can be seen as sexy because it indicates intelligence (people with glasses probably don't play sports so they spend all their time reading/learning instead - its a stereotype that may or may not be true anymore).  But it doesn't have to be so much that you can fix your genetic flaws, as just having good healthcare available seems to be enough to choose partners with less genetic health.  Consider this:

After crunching the data—including the women's facial preferences, their country of origin and that country's national health index—the Face Lab researchers proved something remarkable. They could predict how masculine a woman likes her men based on her nation's World Health Organization statistics for mortality rates, life expectancy and the impact of communicable disease. In countries where poor health is particularly a threat to survival, women leaned toward &quot;manlier&quot; men. That is, they preferred their males to have shorter, broader faces and stronger eyebrows, cheekbones and jaw lines. The researchers went on to publish the study in this month's issue of the scientific journal Proceedings of the Royal Society: Biological Sciences.
To a person unfamiliar with the field of evolutionary psychology, this may sound a little far-fetched. How is it even possible to link a woman's masculinity preferences to the health of her nation? The answer begins with the theory of sexual selection. It goes that women are the choosier sex because they take on most of the risk and burden of reproduction and child rearing. While a man can sleep around with 100 women in a year's time and have 100 kids, a woman who sleeps with 100 men in a year will only have one baby (barring multiples). She has more at stake in each pregnancy. Therefore, it is in her best interest to at least choose a high-quality mate. And one of the hallmarks of a quality male is good health.
But what does health have to do with masculinity? The link is testosterone, the hormone behind manly muscles, strong jaws, prominent eyebrow ridges, facial hair and deep voices. Testosterone is immunosuppressive. This means a man must be healthy and in good condition to withstand its effects on his development. Testosterone is also linked to other traits related to strength: fitness, fertility and dominance. From an evolutionary perspective, masculinity is basically man's way of advertising good genes, dominance and likelihood to father healthier kids. When disease is a real threat, as it had been—and arguably still is—heritable health is invaluable.

http://online.wsj.com/article/SB10001424052748704100604575145810050665030.html
Intelligence, unfortunately, is not associated with health.  Much of what defines attractiveness may depend on evironment factors.  It may not always be the case that physical trumps mental if we're actually smart enough to survive no matter what the physical genetic flaw.  I wouldn't go as far as to say that we're that kind of society yet.  I continue to believe that a certain range of physical characteristics must fall in line regardless how mentally attracted one is.  If you're mentally attracted to someone and then find he is 80 years old (way past breeding age), would you still be attracted?  Evolution-wise, it wouldn't make any sense to be.  Conversely, if you met an incredible hunk of a man, but he had revolting personality and an iq near his shoe-size, he wouldn't be attractive either.  So, I couldn't say one trait has omnipotence, but I do believe the physical has an edge.
Many times we enter into relationships, not out of attraction, but because it makes sense.  The Science of Sex Appeal show also demonstrated that married women dress and dance more seductively than single women as well as having differing hormonal levels (via saliva testing).  The theory proposed to explain this is that once a woman has found a stable and sensible mate, she seeks the &quot;bad boy&quot; because the &quot;bad boy&quot; has the genetic traits for health, but the &quot;bad boy&quot; is a cad for a dad.  So she will get pregnant up by him and make the sensible father (whom she's not all that attracted to) raise the child.
See http://dsc.discovery.com/tv-shows/other-shows/videos/other-shows-science-of-sex-appeal-videos.htm