The test itself is very well done - they try to get people to respond precisely, but checking attention, and asking multiple times questions about the same concept.

However, the article has a very fundamental flaw:

> Unfortunately, most people with extreme levels of dark personality traits don’t want to change who they are. Despite not being particularly happy with their lives

The test doesn't deal with "happiness" at all, which is a key component of the argument.

If consider as example a person like Steve Jobs, who would fair very high on narcisissm and machiavellism, what would be his happiness?

While he could have been as much successful being a nice person (there are examples in history, my favorite being Carmack), what does represent happiness for him, from the perspective of other people, and from his own?

Probably, from his own perspective, he's a "happy" person - he craves attention and success, and he satisfies both.

I think defining happiness in a more general sense requires a certain "wider" personality, which this type of people doesn't have - ultimately, they're very narrow.

Generalizing this example, the argument "Despite not being particularly happy with their lives" doesn't really hold - this type of ferociously and single-mindedly driven people are ultimately succeeding in their own, narrow, purpose.