Menopause is characterized by a prolonged post-reproductive lifespan as is rare among mammals, with clear evidence only in humans and a few toothed whale species (e.g., killer whales). Previous studies suggest that the evolution of menopause can be explained by kin selection, particulary the “grandmother hypothesis”, which proposes that post-reproductive females increase their inclusive fitness by helping their offspring and grand-offspring. We developed an evolutionary, age- and sex-structured mathematical model to determine wheather a menopause-inducing allele can spread in a non-menopausal population via indirect effects on survival and fecundity of younger kin within the social group. Our model incorporates life-history, social structure, and demography, and we applied it to several species: humans, chimpanzees, baboons, elephants, sperm whales and killer whales. Our results show that menopause is expected to evolve in species where older females continue to live with their adult sons and grandsons and substantial contributions to their survival. We therefore propose an update to the grandmother hypothesis, which we term the “mama’s boy hypothesis”, in which helping philopatric, costly males is the key mechanism driving the evolution of menopause.