Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Transcript of sexual orientation
linked with genetic influences, prenatal hormones, and certain brain structures. LeVay
*cell clusters-larger in heterosexual
men than in women & homosexual men
-believes brain anatomy influences sexual orientation
Laura Allen and Rodger Gorski
*section of fibers connecting right and left hemispheres is 1/3 larger in homosexual men than in heterosexual men
*in some brain areas, homosexual men are more likely to have a female-typical neuroanatomy than are heterosexual men
*manipulated a fetal rat's exposure to male hormones-"inverting" its sexual behavior towards rats of the other sex
Jeff Hall & Doreen Kimura
*gay men have fingerprint patterns rather like those of heterosexual women. Most people have more fingerprint ridges on their right hand than on the left. This difference is less true of females and gay males than heterosexual males
-believe is due to prenatal hormones
*gene codes for prenatal hormones and brain anatomy, which predispose temperaments that lead children to prefer sex-typical or sex-atypical activities and friends. These preferences may later lead children to feel attracted to whichever sex feels different from their own. *“nurture” explanations have proven to be inadequate, some psychologists have offered theories that emphasized “nature,” that is, genetic or biological factors. Studies of siblings, including twins, provide one line of evidence for the role of genes.
For example, identical twins are more likely to show the same sexual orientation than fraternal (non-identical) twins. At the same time, it is important to note that even among identical twins, whose genetic make-up is presumably identical, approximately fifty percent of the time the identical twin of a gay man or lesbian is heterosexual. So biology obviously isn’t the whole answer. Experience does seem to play at least some role.
The APA currently officially states that "some people believe that sexual orientation is innate and fixed; however, sexual orientation develops across a person’s lifetime", a radical reversal from the recent past, when non-normative sexuality was considered a deviancy or mental ailment treatable through institutionalization or other radical means. The demographics of sexual orientation are difficult to establish due to a lack of reliable data. However, the history of human sexuality shows that attitudes and behavior have varied across cultures. Two of the most famous studies of the demographics of human sexual orientation were Dr. Alfred Kinsey's Sexual Behavior in the Human Male (1948) and Sexual Behavior in the Human Female (1953). These studies used a seven-point spectrum to define sexual behavior, from 0 for completely heterosexual to 6 for completely homosexual. Kinsey concluded that a small percentage of the population were to one degree or another bisexual (falling on the scale from 1 to 5). He also reported that 37% of men in the U.S. had achieved orgasm through contact with another male after adolescence and 13% of women had achieved orgasm through contact with another woman.
His results, however, have been disputed, especially in 1954 by a team consisting of John Tukey, Frederick Mosteller and William G. Cochran, who stated much of Kinsey's work was based on convenience samples rather than random samples, and thus would have been vulnerable to bias.
Paul Gebhard, Kinsey's successor as director of the Kinsey Institute for Sex Research, dedicated years to reviewing the Kinsey data and culling its purported contaminants. In 1979, Gebhard (with Alan B. Johnson) concluded that none of Kinsey's original estimates were significantly affected by the perceived bias, finding that 36.4% of men had engaged in both heterosexual and homosexual activities, as opposed to Kinsey's 37%. Nature vs. Nurture