The article also says "In reality, all of us are at least a little narcissistic. ", so make of that what you will. Me personally, I'm always cautious when research people claim to have found "truths" about human psychology - which is temporal, transient, highly mutable, highly context-dependent and extremely difficult to generalize.
Coming from a tech background which promotes algorithmic thinking, I have been more than humbled when trying to apply such conceptual frameworks to biological systems at my current job.