Being competitive gets a bad rap and is often associated with stress, anxiety and an overly intense focus on winning or being “the best.” But competition is also a powerful motivator and can increase productivity, improve performance and provide accountability. “Competition at its base is what has driven us as a species to survive,” says Craig Dike, PsyD, assistant clinical director of Doctor on Demand. “It drives biological and physical evolution.”

The theory prevails that social competition led to an increase in the cranial capacity of human beings over the course of time, and a study published in Human Nature examined the reasons for this expansion: Researchers collected data from 153 hominid skulls and examined the global climate changes at the location/time the fossil was found and dated, the number of parasites in the region and the estimated population density.

“Our findings suggest that brain size increased the most in areas with larger populations,” says lead study author David Geary, Ph.D., PsyD, cognitive developmental psychologist and professor at the University of Missouri. “This almost certainly increased with the intensity of social competition.”