I think these conversations about gendered psychological dysfunction usually miss the point.

Narcissism is a cluster b personality disorder, like borderline or histrionic personality disorder. At their core, these 3 cluster b conditions are the same. They all represent the impact of clinging to coping mechanisms that were adopted to deal with severe childhood trauma. Cluster b's real self/inner child/emotional core, pick a term, is so damaged and hurt that they pathologically seek to maintain a shell or false self, that protects their wounded 'inner child.'

The difference is the preferred source of supply. Narcissists will seek status and admiration, and anything that makes them feel flawless and powerful. Borderlines seek anything that causes them to feel like they have a devoted partner caring for them. Histrionics want to feel like the center of attention.

People with any one one of these clinical conditions or tendencies will often vacillate between supply sources, as they become more or less available or more or less stimulating. But the primary supply source, typically determined in childhood and solidified/adjusted in adolescence, comes from the person in question's socialization.

More boys are narcissists or antisocial, because boys are socialized to hide their feelings, be stoic, and appear flawless and omnipotent. More girls are borderline or histrionic because girls are encouraged to over-identify with their feelings, use the faux-vulnerability to get what they want, and seek flattering sexual attention. They have easier access to certain, respective supply sources based on their gender

Trying to quantify this stuff, or argue that x gender is more self-absorbed, totally misses the point. Men and women are as categories are equally damaged, emotionally speaking. We should be spending energy trying to get people to heal themselves, not studying and re-studying which category has more narcissists. It's a moot point.