The missing Soufflé, er, ah, link.
Human life histories, as compared to those of other primates and mammals, have at least four distinctive characteristics: an exceptionally long lifespan, an extended period of juvenile dependence, support of reproduction by older postreproductive individuals, and male support of reproduction through the provisioning of females and their offspring. Another distinctive feature of our species is a large brain, with its associated psychological attributes: increased capacities for learning, cognition, and insight.
And where does it all come from?
Our theory is that those four life history characteristics and extreme intelligence are co-evolved responses to a dietary shift toward high-quality, nutrient-dense, and difficult-to-acquire food resources.
You know, its not easy finding a decent meal. You need big brains for that.