Primate cooperative technical intelligence, aided by language, arose only a heartbeat ago in the cosmic time scale. It's late arrival and explosive growth suggests it was not inevitable, and probably accidental.

Oops, he referred to primates, that's my cue to hold forth on primatology. You have been warned.

I think Henry has it exactly backward regarding the origin of human intelligence. I've been thinking a bit about what it was that got us this far, and I have to give great weight to our unique sociability. He mentions examples of terrestrial species that are very intelligent, yet debatably self-aware and certainly non-technlogical. There's more to it than simple brainpower, and I can't identify a better candidate for that factor than our ability to work together and produce results far beyond the capabilities of any one individual.

Our cooperation isn't always flashy and visible, as when we band together to fight wars or create businesses. Human life is permeated by quiet, patient cooperation that we just take for granted, like teaching each other language and imparting knowledge to the young. Only a social species can engage in education, and without education, intelligence is limited to what an individual can do inside his/her own head.

Humans didn't get smart because of the gift of a chance mutation*, we got smart because we've spent a million years teaching each other how to be smart, and exercizing the faculty together. We developed intelligence and self-awareness because we've worked hard at it.

(*--Of course there were many small mutations, but they could only take hold because our sociability provided a congenial environment for the mutation. A mutation that conferred language, for example, on a member of solitary species like the cat family would be entirely wasted.)

I try to imagine how the fictional Klingons could have developed a technological civilization, and I have a hard time with it. When in their history did they stop killing each other long enough to develop science and technology?

My point regarding the odds of technological sapience is that I don't think it's just a freakish mutation, but that it's explainable and understandable as a synergistic effect of the interactions of social creatures over a long period of time. We have plenty of evidence on Earth that social behaviors aren't a rare fluke, but one of a spectrum of successful strategies for species survival. We've taken it farther than wolves and whales and our primate cousins, but our sociability is not unprecedented.

So I would put it in Drakish terms by saying that 1) raw intelligence is likely to arise due to simple competitive pressures; and 2) the odds of that intelligence being boosted to sapience and tool use by social behaviors are quite high. In any given ecology, it's likely that some species will adopt social strategies, and some of those will have the potential to develop big brains.