The article itself is a little long and all over the place, but it makes some interesting points and some even more interesting conclusions. One of which is that Machiavellians do more "mentalizing" than other people, "cognitively strategizing, scheming, and trying to infer the intentions of others," presumably to stay one step ahead. Another seems suspect:
For most of our evolution, it payed to be cooperative and empathic. But during the course of our evolution, there were also selfish individuals who learned how to manipulate others to get what they wanted. They lacked empathy, perspective taking, and self-awareness (i.e., metacognition). Still, they had in tact lower-level perceptual theory of mind abilities that were good enough for them to manipulate others. In fact, their lower levels of empathy and higher levels of strategizing and spontaneous mentalizing worked to their advantage: whereas most people intuitively felt as though they were doing something wrong when they hurt others, these Machiavellian individuals didn't recieve [sic] the same emotional signals so they persevered toward their short-term selfish goals. In the process, they obtained more quantity of mates. Therefore, they remained in the human gene pool, along with their short-term mating orientation.
I can see that narcissists lack self-awareness, but what about Machiavellians and psychopaths? I'm sort of underwhelmed by this guy's reasoning. And he is a cognitive psychologist at NYU. So credentials in the psychology world don't mean much?
But here's something else interesting I didn't know:
Andrew Whiten and Richard Byrne argue that primate intelligence stems from "Machiavellian Intelligence" -- the ability to manipulate and deceive others in the competition for scarce resources.