Oxytocin is a peptide hormone and neurotransmitter that plays an important role in regulating the process of carrying a fetus, childbirth and lactation. It is also associated with influencing emotional attachment with others and social behavior, including recognition, empathy, trust, sexual activity, and the forming of bonds and relationships.
Oxytocin is produced by cells in the brain’s hypothalamus and released to another area of the brain called the posterior pituitary. It sends the hormone out to different areas of the body that have proteins known as oxytocin receptors which can trigger physical responses such as contraction of uterine muscle and the secretion of milk.
All mammals produce oxytocin and females typically have higher levels than males. Increases in oxytocin have been detected during the formation of bonds between different species too, for example humans and dogs. Similar chemical hormones have been found to influence social behaviors in other animals, including fish, birds, and molluscs.