… if you’re a locust, that is. When the droughts make times tough for the normally solitary little critters, they get packed close together, and a sort of insect mob law takes over in response to a flood of serotonin – swarm time! This change to a more risky social lifestyle demands more brain power from the individual locusts, and their brains expand to cope.
Immediate parallels thrown up by my own brain: Teilhard de Chardin’s noosphere; Clarke’s Childhood’s End. Putting on an uncritically optimistic technophiliac hat for a moment, might we imagine the increased global socialisation enabled by modern communications networks to provoke some similar expansion of human brain capacity?
We might… but bear in mind the locust’s brain-boost is necessary to cope with a life where fierce resource competition and cannibalism is the norm. Hey presto: a grimly allegorical sf dystopia that writes itself!