Throughout most of human history, you didn't get some unless you had some. More precisely: it was wealthy, powerful men who scored the most sexual mates and, therefore, fathered the most offspring. Men with less wealth and low standing, meanwhile, died disproportionately childless. (As for women, they had little choice about sex regardless of status, since men treated them as property.)
Many evolutionary scientists believe that those thousands of years of human behavior are no artifact: modern men still strive for status partly because it is an evolutionary advantage for improving reproductive success. But other researchers have disputed that theory by citing data showing that wealthier, higher-status men do not in fact have more children than their less moneyed, lower-status peers. (See pictures of Barack Obama's family tree.)
Now a new study in the Journal of Personality offers another theory: it is not necessarily wealth that facilitates procreation but a more basic and deeply ingrained evolutionary trait — having a Type A personality. The study finds that adolescents who say they always take charge, tell others what to do, anger quickly, get into fights easily, and walk, talk and eat fast end up having more kids than others when they grow up. That's true regardless of the kids' performance in school.
This is terrible news for nerds, since it implies that in the end, even if they go on to invent software or write Lost episodes or produce great books, the bullies and jocks will win in a far more primal way: they spread their genes to more little bullies and jocks. Call it the ultimate victory of Attila the Hun.
The authors of the study, psychologists Markus Jokela and Liisa Keltikangas-Järvinen of the University of Helsinki, interviewed 1,313 Finnish men and women who were participating in a long-term study on an separate topic (cardiovascular risk). The participants underwent psychological assessments first when they were young (between the ages 12 to 21) and then again 18 years later. Those young people with more Type A personality traits ended up having significantly more children by age 39. (The math is complicated, but for those readers who are statistically minded: for every standard deviation of increase in Type-A traits, the probability of having kids rose 11% in men and 19% in women.) (See pictures of U.S. presidents and their children.)
The research suggests that leadership qualities like taking charge and being competitive have an evolutionary advantage even if high socioeconomic status no longer does. "Perhaps the idea of having children is most attractive (or least frightening) to individuals who prefer to act as leaders and to influence other people, including their own offspring," the authors write. The theory is that evolution genetically predisposes Type A's to like having kids because thousands of years ago, people with Type A personalities accrued more resources to guarantee their kids' survival.
The paper offers new insight into an evolutionary conundrum posited in 1986 by Daniel Vining Jr. of the University of Pennsylvania in the journal Behavioral and Brain Sciences. Vining pointed out that in contemporary societies, rich couples have the same number (and often fewer) kids than poor ones. The article suggested that human reproductive behavior was entirely learned, not inherited.
The most notable challenges to that perspective have been put forth in recent years by sociologist Rosemary Hopcroft of UNC Charlotte and evolutionary psychologist Satoshi Kanazawa, who now teaches at the London School of Economics and Political Science (LSE). In a 2006 article in the journal Evolution and Human Behavior, Hopcroft showed that after you account for children born to mistresses and second (or third, or fourth...) trophy wives, rich men do have more kids than poor men. And Kanazawa, in a 2003 Sociological Quarterly paper, noted that even if wealthy men don't have more kids within marriage, they have more sex partners total — and more sex with each partner — than poor men.
Today's moguls, then, differ only in degree from the prolific breeders of the past, such as Moulay Ismail the Bloodthirsty, Emperor of Morocco, who produced at least 700 sons (people stopped counting after that) and an untold number of daughters before he died in the early 17th century. One big reason today's powerful men don't have as many kids as they could is a relatively new invention that our reproductive instincts haven't had time to adapt to: contraception. (See pictures of classic stars' families at LIFE.com.)
The new paper shows that the debate over Vining's theory may be beside the point, since it is not wealth per se but a forceful, take-no-prisoners personality that has the genetic advantage. To be sure, many Type A's turn out to be wealthy, but we all know plenty of Type A's who live average lives (think of your persnickety high-school math teacher, or that Type A mom down the street who slices the carrots for the lunch box just so.
As for nerdy, studious guys, the research suggests they can't expect to be fruitful unless they become more like the bullies who tormented them as boys. That's because, as past studies have shown, the higher your intelligence, the less sex you tend to have — and, therefore, the fewer kids you will have. The last 20 years have been a golden era for dorks as video games and graphic novels and software engineering have become respectable, even mainstream. But in the end, the brutish football players who tormented them in high school will likely win in the merciless world of genetic favor.