Definition:
One of the explanations for the post-menopausal life stage of human females (and general long lives of humans), a life stage that does not exist in any non-human primate. It is hypothesized that the evolution of grandmothers is an advantage for humans. Grandmothers who invest energy into the offspring of their children reduce the reproductive cost of parenting through social kin-networking. This can further off-set the resource cost of childrearing and brain-building as parents are freed to provision for resources. An increase in resource procurement may reduce the inter-birth interval by allowing for earlier weening and more offspring production.
