Something you have to post immediately if you see it at two a.m.

I'm generally not that impressed with this sort of thing but obviously I have to post this.

From Psychology Today:

There is thus no indication in any of the ethnographic evidence that any sustained nocturnal activities occur in traditional societies, other than occasional conversations and singing, in these tribes. It is therefore reasonable to infer that our ancestors must also have limited their daily activities to daylight, and sustained nocturnal activities are largely evolutionarily novel. The Hypothesis would therefore predict that more intelligent individuals are more likely to be nocturnal than less intelligent individuals.