They did one study where they found people who take more selfies have higher levels of narcissistic traits.
In both studies, participants' total narcissism scores, and measures of all of the narcissism subscales except for Self-Sufficiency, were positively correlated with selfie-posting for men; this was true for all three types of selfies examined. For women, a different picture emerged:Only the Admiration Demand subscale predicted selfie-posting (solo selfies in the first study and selfies with romantic partners in the second study).