What do men want?Biology’s simple answer is that men want to survive to pass on their genes. But when you throw this goal into a complex society of competing men, discerning women and morality, biology gets confused.For better or for worse, behavioral economics has the answers.Basically, behavioral economics considers animal mating as a free market, heavily influenced by supply and demand. For example, because the nature of pregnancy, birth and nursing means that female mammals must invest more time and energy in reproduction than males, a male mammal’s reproductive potential is bound by the number of mates he can find, while a female mammal’s reproductive success is bound by the time/energy it takes to successfully raise her children. (In exceptional societies like that of the red-necked phalarope in which males raise the offspring the reverse is true—females compete for males and guard them jealously.)If ye olde supply and demand were the end of the story, it would lead to ever-philandering human males fighting for access to women, who would have as many children as they could feed. In fact, this model describes chimpanzees and bonobos, our closest relatives, pretty well (and is why male primates are larger than their female counterparts).And historically, the availability of resources did, in fact, influence whether human societies were monogamous, polygamous or polyamorous. First, in cultures that evolved in resource-rich areas, females didn’t need male help to raise their children and thus gave little preference to males who would stick around to share the burden (these males, unfettered by paternal investment, quickly went in search of additional mates, but supply and demand meant they needed to fight for them); second, in resource-poor environments, women needed the contribution of hunting men and it was all a dude could do to put enough meat on the table to feed a single family, thus monogamy and paternal investment. And finally, in societies where men had access to resources while women did not, polygamy developed—women needed (or were forced to need) male resources in order to raise their children, and certain men could supply these in enough quantity to support many women.Now, hypothetically, imagine the ideal reproductive circumstances for women: male competition and paternal investment amid ample resources. Hmmm, this sounds vaguely familiar. Wait a minute! This is modern society, in which men spend resources parenting when they could be off further procreating.In short, men have been biologically bamboozled. But how?The first step is regulation of the free market. Morality performs the role of the SEC, dictating that men enter monogamous relationships despite hampering their reproductive potential. (How this morality developed is up for debate.) At least society increases paternal certainty——if men are to subjugate their reproductive potential to the dictates of morality, then at least they can be certain the children in whom they are over-investing are their own. (When men distrust the assurances of society, it leads to sexual jealousy and mate guarding.)But morality can’t explain it all: with a surplus of resources and the socially dictated potential for only one mate, men shouldn’t need to butt heads, lock antlers, build bowers or otherwise compete for female attention. What then of football? And of Gold’s Gym and singles bars and law school?It turns out that female homo sapiens sapiens are tricky and have developed the behavioral ability to combat ecology and morality. Specifically, women have become picky and wary of casual sex that could cause pregnancy. Thus women hold their reproductive cards tightly, and will show their hands only to men of their choosing, forcing men to compete even for the opportunity to mate with just one woman. Women maximize their reproductive potential by wisely choosing men who demonstrate the potential for paternal investment.But women don’t have it as easy as they might, either. According to the rules of good old Darwinian free market ecology, women should be able to sit back (with their legs tightly crossed and/or their birth control firmly in place) and wait for suitors to come suiting. But while the ecological math of monogamy means that women may have only one suitor, women continue to compete for the most suitable suitor.This isn’t always pretty.But unlike men who prefer whacking each other with sticks, the major model of the modern major female reproductive competition is to exclude competing women from social groups that ensure successful mating. This, in a nutshell, is why middle school sucks.This model of human mating assumes an equal number of men and women. But what if this weren’t the case? We see in periods of male scarcity, as during the Vietnam War, that when men are scarce and thus in higher demand they tend to influence the reproductive mores of society towards a higher degree of sexual liberalism, thus increasing male reproductive potential, and thus Woodstock and free love.Apologies to Cupid, but humans remain mired in a wild, wild world, in which our reproductive success determines many of our actions.Join me every Monday morning for more grandtastic goodies from The Geeks' Guide to World Domination . Or if you like your geekery delivered fresh, consider subscribing to my rss feed or joining my Facebook Fan Page