Laurie Santos is an associate professor of psychology and the director of the Comparative Cognition Lab at Yale University, which focuses its research on the evolutionary origins of the human mind. In this brief talk, Laurie Santos discusses what she calls a "puzzle" for humans, attempting to determine what is more natural: pair bonding or polygamy.
According to Santos, pair bonding is most common in the animal kingdom in birds, exemplified in 'The March of the Penguins.' This is due to the size of the offspring, but also the fact that the egg needs defending from predators and incubating to ensure healthy growth.
While there is a push in society for polygamy and there is beginning to be a bit of a push for polyandry, Santos says it is difficult to determine in humans as we know a lot more about the mating habits of the animal kingdom.