I spend so much time tearing into other people's ludicrous claims on here that I thought I'd espouse some of my own; these are to some degree a tongue in cheek stab at the less scientific aspects of evolutionary psychology, while also being an unsupported hypothesis of my own.
Humans are much like lemmings. Not in the sense that we're small rodents, but in the sense that we are the animals in the urban legend about creatures that are so blindly obedient to their programming as to follow one another over a cliff edge. We're so enamoured with disaster (see a large portion of what is put out as entertainment by Hollywood) that we sidle closer to whatever the disaster is with a curious expression on our faces. Humans are the ones who hear an odd noise in the night, and rather than hiding sensibly, we go to investigate it only to be shot by the person who merely wanted to make off with the silverware. We slow down to sneak a peek at the carnage at the scene of a car accident, sometimes causing another in our distraction. People escalate what should be mild disagreements over things like, oh, putting our glass in the wrong spot in the bar or flirting with someone's significant other (often without knowing that he or she is attached) into a life and death struggle, or at least what would be without the intervention of people paid to do so. Our territorial pissings and petty jealousies are part of our programming, as much as the lemmings' programming (in urban legend at least) is to follow the same ancient migration routes without regard for where they actually lead now.
Now, while this is based on simple observation, one can promote a hypothesis from the ideas above. Perhaps people are so stupid as to stand around the burning building that has a fair chance of exploding not out of curiosity, but because we are all imbued with the propensity to ignore danger because it helps the rest of the species when some of us act that stupidly. This is naive group selection at its finest, but doesn't require that there are different behaviours programmed in us, rather that we all share that tendency from a distant common ancestor, and that it has prevented human overpopulation in times of famine, climate change, etc.
Take it with a grain, nay a shaker, of salt.