Why are humans born weak, in need of care, unlike in most animals? Is one of the main reasons that humans have developed easier, more convenient lifestyles, climbing up the food chain and thus warranting a shorter or less demanding pregnancy, pushing more of the necessary growth of a child to occur outside of the womb, and thus producing very weak babies at birth compared to other animals? Theory: Across evolutionary timeframes (thousands of years at least), the more women are expected to engage in demanding work (especially mentally complex work), the more the offspring is born physically weak (that is, physically weak at birth but not necessarily later.) I hypothesize that mental energy somehow drains the woman’s capacity to reproduce healthier children (that is, not in a single or a few generations but, more evidently, across thousands, or perhaps as fast as hundreds, of years). In this sense, we can say that there are women who are most optimally suited for high-pressure cerebral work and there are women who are most optimally suited for producing fitter children, and that those two roles are supposedly mutually exclusive. Although the cerebral high-pressure female capacity seems to be much newer than the healthy-child-bearing female capacity (reflecting that it’s still a man’s world, so to speak), I think the two types of tendencies, genetically speaking, will continue to exist in varying degrees across time, because both are increasingly needed. I also hypothesize that the new role (the mentally demanding one) will grow, fuelled by increased financial demands, greater potentials for self-actualization and technological advances in human reproduction (i.e. IVF, cloning, genetic engineering, etc.) which may become alternatives to good ol’ missionary.