Twenge, J. M., Konrath, S., Foster, J. D., Keith Campbell, W., &Bushman, B. J. (2008). Egos inflating over time: A cross‐temporal meta‐analysis of the Narcissistic Personality Inventory.

ABSTRACT A cross‐temporal meta‐analysis found that narcissism levels have risen over the generations in 85 samples of American college students who completed the 40‐item forced‐choice Narcissistic Personality Inventory (NPI) between 1979 and 2006 (total n=16,475). Mean narcissism scores were significantly correlated with year of data collection when weighted by sample size (β=.53, p<.001). Since 1982, NPI scores have increased 0.33 standard deviation. Thus, almost two‐thirds of recent college students are above the mean 1979–1985 narcissism score, a 30% increase. The results complement previous studies finding increases in other individualistic traits such as assertiveness, agency, self‐esteem, and extraversion.

 

 

Twenge, J. M., Konrath, S., Foster, J. D., Keith Campbell, W., & Bushman, B. J. (2008). Egos inflating over time: A cross‐temporal meta‐analysis of the Narcissistic Personality Inventory. Journal of personality, 76(4), 875-902.

https://doi.org/10.1111/j.1467-6494.2008.00507.x