2. An analysis of the Nature vs. Nurture debate on Homosexuality By: Ally Stanhope SBI4U

3. Homosexuality: sexual desire or behaviour directed toward a person or persons of one’s own sex. http://www.istockphoto.com/file_thumbview_ap prove/8168607/2/istockphoto_8168607-gay- pride-gender-symbols.jpg

4. Possible Causes of Homosexuality http://www.cdc.gov/ncbddd/BD/images/gene tics.jpg http://extension.umd.edu/images/family.jpg

5. Pedigree study : Dean Hammer Twin Study : J. Michael Bailey and Richard C. Pillard Hormone Experiment : Richard Green and Ronald Hellmann http://deathby1000papercuts.com/wp- content/uploads/2009/04/3d_model_dna_w_phosphate_1.j pg

6. Dean Hammer’s Study Studied the pedigrees of 32 pairs of brothers that were both homosexual http://faculty.ucc.edu/biology- atsma/pics/pedigree.gif Determined the “homosexual gene” is passed on from mother to son Studied the brothers’ DNA 2/3 (22 out of the 32 sets) of the brothers shared exactly the same type of genetic material Discovered that a majority of the brothers shared the same sequence on the Xq28 region of the X chromosome.

7. Twin Study 56 pairs of identical twins, 54 pairs or fraternal twins, 57 pairs of non-biological siblings who lived with adoptive parents. (all males) studied the sexual preferences of sets of twins where at least one twin was homosexual 52% of the identical twins both shared the same homosexual preference 22% of the fraternal twins both shared the same homosexual preference 11% of adopted twins both shared the same homosexual preference http://river66.files.wordpress.com/2008/04/identical- twins.jpg

8. Twin Study Continued 48% of identical twins were both homosexual 16% of fraternal twins were both homosexual 6% of non-biological siblings were both homosexual

9. Hormone Study studied 17 heterosexual men, 14 homosexual men, and 12 heterosexual women http://4.bp.blogspot.com/_s03XW1ZvVvE/Sp9 wdnP8AMI/AAAAAAAAAo0/yvCO_C7Osi w/s400/brain-1.jpg all participants had estrogen injections After 4 days…. women’s luteinizing hormone level was 200% of baseline values heterosexual male’s values were 88% homosexual male’s were 138%

10. http://www.wikidoc.org/images/6/6f/Sigmund_Freud -loc.jpg

11. today’s generation is more accepting of homosexuality there are still people, for example members of religious groups, that do not believe in homosexuality with today’s technology, people who do not believe in homosexuality could have their child’s genes altered, like a designer baby, if a specific gene was found to cause homosexuality.

12. References Steen, Grant R. DNA & Destiny : Nature & Nurture in Human Behavior. N.p.: n.p., 2001. N. pag. Science Reference Center. Web. 8 Nov. 2009.. Bower, B. "Gene influence Tied to Sexual Orientation." Science News: 6. Science Reference Center. Web. 6 Nov. 2009.. Silberner, J. "Hormone Marker For Homosexuality?" Science News: 198-199. Science Reference Center. Web. 8 Nov. 2009.. Newman, Dara. "The Genetics of Homosexuality." Serendip. N.p., 18 Jan. 2008. Web. 6 Nov. 2009.. "Twin Studies and Homosexuality." World Policy Institute. N.p., n.d. Web. 8 Nov. 2009..