The deceleration and increased cohesion of the Dark Triad traits over the life course

In two studies (N = 1,747; N = 701), cross-sectional data from Canada and America were gathered from college students and MTurk (respectively) to understand the relationship between the age of the participant and scores on the Dark Triad traits (i.e., narcissism, psychopathy, and Machiavellianism). Age had a number of important effects on Dark Triad traits. First, older samples scored lower on the narcissism and psychopathy; effects that were stronger in men than in women. Second, age was negatively correlated with the Dark Triad traits; associations that were generally uniform across the sexes. Third, the variance between scores on each trait was larger at younger ages than older ones in both sexes. These results are consistent with and discussed within a Life History approach on the Dark Triad traits taken by some evolutionary psychologists studying these traits.