Definitions - behavior vs. preference
Sexual behavior amongst members of the same sex
Homosexuality = enduring sexual preference for member of same sex
Culturally defined
Behavior = common in animal kingdom and within humans, enduring preference is not
Behavior vs. Social Identification
Ford and Beach (1951) - homosexual behavior normative in 64% of cultures
Approx. 20% of people report having homosexual feelings or experiences at some point
Only 2-6% in most western cultures identify as homosexual
Homosexuality in Ancient Greece - pederasty
Sexual orientation not seen as a social identifier
Gender of sexual partners not important - role (penetrator vs. penetrated) important
Relationships between men of same age and status frowned upon.
Ancient Greece - most common form = pederasty (12-17 yea
Homosexuality in Rome - age and status based
Graphic depictions less common than Greece
Sexual encounters with slaves
Pederastic relationships lost their "educational" status, acceptance varied.
Passive/active role usually based on age/status
Like Greece - lesbianism frowned upon and not well docume
Homosexuality and religion
Current doctrines of world's largest religions generally have negative views
Abrahamic religions have traditionally viewed sodomy as a sin
Judaism - varies
Catholicism - requires people attracted to same sex to practice chastity
Islam = natural temptation
Fraternal Birth Order
Ray Blanchard
Men only
Each additional older brother increases odds of being homosexual by 33%
1 in 7 gay men
Being raised with brothers not important
Maternal environment during gestation
Evolutionary Explanations - side effect, alliance formation
Reduced reproductive success why still here?
BUT: Some theorists (e.g., Michel Foucault) state that homosexuality is a social and historical construction - not found prior to 18th century, not found in most non-western cultures, "'Sexuality' is an invent
Evolutionary Explanations - alliance formation
Kirkpatrick (2000)
Reciprocal altruism
Same sex alliances aid survival and subsequent reproduction - fairly strong support
Homosexual behavior aids in alliance formation - moderate support
Bisexuality is more common than homosexuality - strong support
Evolutionary Explanations- side effect
Vasey 1995
By product of selection for sexual pleasure
= exaptation, not built by natural selection for the benefits it accrues today (e.g., alliance formation etc)
Xq28 gene - implications, problems with research
Twin studies
52% non-heterosexual monozygotic co-twins also non-heterosexual
22% fraternal twins
X-linked?
Xq28 region similarity in 33/40 sibling pairs
Dubbed "gay gene" - problems? (what are the problems?)
Not replicated in all subsequent studies
Penguines
In captivity - intensely bonded male penguins, build nests, use stone as egg substitute
Will not bond with female if separated
Not known in the wild as impossible to determine sex
Bonobos
Pan paniscus
Highest frequency of homosexual behavior
Matriarchal species
About 60% of all sexual activity is between females
Social functions - tension reduction, social bonding
Japanese Macaques
Macaca fuscata
Females
Consortships ( < 1 hour- 1 week), sexual mountings, synchronized behavior
Not due to lack of available males
Varies by population
Not related to dominance (mounting and thrusting bidirectional)
Dominant females not necessarily sough