The opposite could also be true: Our brand of intelligence - the combination of brains and dexterity and environment that let us quickly advance from sophistic

The opposite could also be true: Our brand of intelligence - the combination of brains and dexterity and environment that let us quickly advance from sophisticated tool building to a global industrial economy - is precisely the rare Goldilocks combination of features that allows a civilisation to spread throughout the universe. Because that combination is incredibly rare we might very well be the first to be poised to attempt to do so. This is the strong anthropic principle at play, which of course could be taken with a grain of salt. Still, this scenario nicely answers the question "Where is everyone?", too.