Hmmmm.....Interesting but troubling research. In my humble opinion, I think we are veering into territory where we need to start to provide some serious definitions around narcissism. This research seems to suggest that "normal" parents today are contributing to narcissism in children by "overpraising" and "overvaluing them". The study focuses strongly around the concept of self-centeredness and selfishness which is, of course, at the heart of true narcissism. But it does so without addressing in any detail the behaviors and health of the parents. Could one or both of the parents in this study be deemed NPD? Certainly, no parent with NPD that I've ever seen or heard of would ever "overpraise or overvalue" their child.
There's no question that society today is contributing to narcissistic TRAITS in children via social media, parenting and education styles and priorities driven by images of celebrity and fame. BUT that is far different than the impact of being raised in a truly NPD household. In those cases, much more than just selfishness and self-centeredness is going on. The impact is life-long on those children and often involves emotional and/or physical neglect that result in a whole menu of negative results for children as they grow into adulthood.
Research like this and other similar media coverage serves to trivialize NPD. There's no doubt an increase in narcissistic traits in children can and will lead to negative consequences for them and for our society. However, NPD is far more serious and a whole other ball of wax. Narcissism should be better defined and discussed, perhaps, in terms of a "spectrum". Only then can parents, educators and others truly address the problems effectively and/or have proactive discussions on what constitutes healthy, appropriate parenting behaviors.
It's time to focus on the "disordered" part of NPD and not just the selfishness characteristics that society seems to be focusing on today which is too easily excused by a focus on social media and changing societal priorities.
Finally, I'm very familiar with the nature vs. nurture concept of NPD. In my view, it is only "genetic" in the sense that if a family fails to break the cycle, the narcissistic pattern will continue. It starts and ends with parenting and the relationship between parent and child. In order to break the cycle, as a society, we have to start thinking more seriously about NPD. That means talking intelligently about it in the media, addressing it in terms of a spectrum and NPD types, and, especially, focusing on ways to identify it early on and help children to deal with it (both in adolescence and adulthood). It's a very difficult disorder to address since those with NPD tend to hide it from the public so well. Also, there is little discusson of the negative consequences of ongoing NPD--among individuals, families and to society.
Certainly, I've had much difficulty finding therapists who truly understand NPD, let alone how to treat those affected by it. Superficial studies that focus only on narcissistic traits (and selective ones at that) certainly are not helping matters.
Just my two cents.