Population density affects how lives are lived. Sng and his colleagues report that “The world population has doubled over the last half century. . . . Across nations and across the U.S. states . . . we find that dense populations exhibit . . . greater future-orientation, greater investment in education, more long-term mating orientation, later marriage age, lower fertility, and greater parental investment. . . . experimentally manipulating perceptions of high density led individuals to become more future-oriented. . . . experimentally manipulating perceptions of high density seemed to lead to life-stage-specific slower strategies, with college students preferring to invest in fewer rather than more relationship partners, and an older . . . sample preferring to invest in fewer rather than more children.”
Oliver Sng, Steven Neuberg, Michael Varnum, and Douglas Kenrick. “The Crowded Life Is a Slow Life: population Density and Life History Strategy.” Journal of Personality and Social Psychology, in press.