Love, lust, and physical intimacy: oxytocin and the contraction of involuntary muscles

Among other things, love can refer to care for a child or to sexual desire. This curious linguistic association probably reflects the evolutionary repurposing of machinery that established and maintained the ancient bond between mothers and offspring for the establishment and maintenance of romantic bonds between sexual partners. Oxytocin has been implicated in both kinds of bond. I propose that oxytocin possessed an ancestral function in gamete release and that the earliest form of attachment to offspring was a suppression of appetite after spawning to prevent parents from eating their progeny. Maternal care has been greatly elaborated since this simple beginning. Human infants elicit feelings of care because of their helplessness which has been ascribed to their neural immaturity at birth which has, in turn, been ascribed to problems associated with the delivery of a large-brained infant through a narrow birth-canal. I propose instead that the helplessness and hairlessness of human infants were adaptations of ancestral infants to obtain better care by being held close to warm maternal bodies.