Most research on the development of personality traits like the Dark Triad (i.e., narcissism, Machiavellianism, and psychopathy) focuses on local effects like parenting style or attachment, but people live in a larger society that may set the stage for any local effects. Here we paired nation-level data on the traits from 49 nations with several milieu indicators (e.g., life expectancy, homicide rates) from thr...