Oxytocin
Oxytocin (Oxt) is a peptide hormone and neuropeptide. Oxytocin is normally produced by the paraventricular nucleus of the hypothalamus and released by the posterior pituitary. It plays a role in social bonding, sexual reproduction, childbirth, and the period after childbirth. Oxytocin is released into the bloodstream as a hormone in response to stretching of the cervix and uterus during labor and with stimulation of the nipples from breastfeeding. This helps with birth, bonding with the baby, and milk production. Oxytocin was discovered by Henry Dale in 1906. Its molecular structure was determined in 1952. Oxytocin is also used as a medication to facilitate childbirth.
Human bonding
A study in 2003, by the U.S. Department of Defense, based on human-animal bonding determined that there was an improvement and enrichment of life when animals were closely involved with humans. The study tested blood levels and noticed a rise in Oxytocin in humans and animals which participated; Oxytocin has the ability to lower stress, heart rate, and fear levels in humans and animals.