Most animals will only engage in sexual activity that can result in reproduction. There are some exceptions; Bonobos, for instance, engage in a lot of sexual activity that does not involve coitus. ...
This study Oxytocin Modulates Social Distance between Males and Females examines the effects of Oxytocin (OXT) on men in monogamous relationships. It demonstrates that OXT assists in maintaining ...
In some research papers, transsexuality is correlated with measurable differences in brain structure. For example: Zhou et al. (1995) inspected the central subdivision of the bed nucleus of the ...