Actually the default age for most men is 3-1/2. You do get a few who only manage to reach 2-1/2 and they have a tendency to throw their toys out of the pram, but 3-1/2 is all right, because the ones who do manage to reach 6 have a tendency to be rather boring.
This is no mere hypothesis. It is a proper theory, worked out from 64 years of empirical evidence.