Homosexual Behavior

Certainty Style Key

Certainty styling is being phased out topic by topic.

Hover over keys for definitions:
True   Likely   Speculative
Human Uniqueness Compared to "Great Apes": 
Relative Difference
MOCA Domain: 
MOCA Topic Authors: 

Homosexual behavior has been reported in all of the Great Apes, for both males and females, adults and juveniles, in captivity and in the wild, although exclusive engagement in homosexual behavior may be unique to humans. Homosexual behavior, same-sex genital contacts or manipulation, likely functions in several contexts in the Great Apes, including: dominance, tension regulation, reconciliation, and social bonding. Homosexual contacts in primates can include ventro-dorsal and ventro-ventral mounting, genito-genital (g-g) rubbing, manual-genital contact, and oral-genital contact, and may also be accompanied by penile erection and ejaculation, as well as female orgasm.

Universality in Human Populations: 

Homosexual behavior is likely universal in human populations. It is more common, or more commonly acknowledged, in human societies in which it is not perceived of as an abnormal or aberrant behavior.

Occurrence in Other Animals: 

Homosexual behavior has been observed in mammalian and avian species and appears to be particularly common among marine mammals.

Related MOCA Topics
Referenced By:


  1. Male homosexuality and maternal immune responsivity to the Y-linked protein NLGN4Y, Bogaert, Anthony F., Skorska Malvina N., Wang Chao, Gabrie José, MacNeil Adam J., Hoffarth Mark R., VanderLaan Doug P., Zucker Kenneth J., and Blanchard Ray , PNAS, 2017/12/11, (2017)
  2. Female Genito-genital Rubbing in a Group of Captive Chimpanzees, Anestis, S. F. , Volume 25, Issue 2, p.477 - 488, (2004)
  3. Homosexual behavior in wild Sumatran orangutans (Pongo pygmaeus abelii)., Fox, E A. , Am J Primatol, 11/2001, Volume 55, Issue 3, p.177-81, (2001)
  4. Homosexual behavior in primates: A review of evidence and theory, Vasey, P. L. , Volume 16, Issue 2, p.173 - 204, (1995)