EAST LANSING, Mich. -- Young women in America are often told not to settle for a man who makes them anything less than 100 percent happy. But a new study has found that settling for "Mr. Pretty Good" is a better evolutionary strategy than holding out for Mr. Right.
Michigan State University researchers found that human nature contains a strong element of risk aversion -- that is, a tendency to take the safest bet when stakes are high. This encouraged primitive humans to settle for a currently available mate, since waiting for something better to come along increased the risk that the human might never mate at all.
"Primitive humans were likely forced to bet on whether or not they could find a better mate," said Chris Adami, MSU professor of microbiology and molecular genetics and co-author of the paper.
"They could either choose to mate with the first, potentially inferior, companion and risk inferior offspring, or they could wait for Mr. or Ms. Perfect to come around," he said. "If they chose to wait, they risk never mating."
And it seems that this impulse is very much alive today.
Adami and his co-author Arend Hintze, MSU research associate, used a computational model to trace risk-taking behaviors through thousands of generations of evolution with digital organisms. These organisms were programmed to make bets in high-payoff gambles, which reflect the life-altering decisions that natural organisms must make, as for example choosing a mate.
"An individual might hold out to find the perfect mate but run the risk of coming up empty and leaving no progeny," Adami said. "Settling early for the sure bet gives you an evolutionary advantage, if living in a small group."
Their findings: How risk averse we are correlates to the size of the group in which we were raised. If reared in a small group -- fewer than 150 people -- we tend to be much more risk averse than those who were part of a larger community.
It turns out that primitive humans lived in smaller groups of about 150 individuals.
"We found that it is really the group size, not the total population size, which matters in the evolution of risk aversion," Hintze said.
However, not everyone develops the same aversion to risk. The study also found that evolution doesn't prefer one single, optimal way of dealing with risk, but instead allows for a range of less, and sometimes more-risky, behaviors to evolve.
"We do not all evolve to be the same," Adami said. "Evolution creates a diversity in our acceptance of risk, so you see some people who are more likely to take bigger risks than others. We see the same phenomenon in our simulations."