January 26, 2013
To the question, "Why is the human species only as intelligent as it is, and not more so?", Charlie Stross answers, tl;dr:
...we only need to be smart enough to understand and use the cognitive tools created by our most intelligent outliers.
And it is because of language, the non-physical transmission of information, super-genetic.
"The evolutionary pressure selecting for general intelligence (to the extent that general intelligence exists) breaks once a species develops language."
"And a logical corollary of this hypothesis is that we are only just smart enough, on average, to be capable of horizontal transfer of memes. Once language and culture arrived (note specialized usage of term 'culture'), we didn't need to get any smarter: we could "borrow" from one another. Therefore we're only just smart enough to do this."
-Charlie's Anthropic Stupidity Hypothesis