PSYCH 3F03 Lecture Notes - Lecture 13: Twin Study, Antibody, Chinstrap Penguin

• School: McMaster University
• Department: Psychology
• Course: PSYCH 3F03
• Professor: David Feinberg

Document Summary

Same-sex sexual behavior is not a dead end, this is misinterpretation of evolutionary theory. Natural selection does not only occur via evolution via direct descent. Evolution via kin selection promotes genes outside of direct descent. Same-sex sexual behavior is: not maladaptive, not evolutionary mistake or dead-end, prevalent across animal kingdom, adaptive for many reasons. By producing offspring who prefer same-sex, we don"t decrease repr. Net effect is increasing number of copies of genes in subsequent generations via indirect selection. Twin studies: compare rates of homosexuality between mono and dizygotic twins, rates higher in mono (r=1, vs di r=0. 5, rates of inheritance determine homosexuality is in part inheritable. Species that exhibit same sex sexual behavior: african bat bugs, bonobos, bottlenose dolphins, chinstrap penguins, flour beetles, fruit flies, garter snakes, guppies, nematodes, rams, zebra finch. Remember naturalistic fallacy providing non-adaptive explanations does not imply value judgment. Only seeks to explain whether same sex behavior leads to increase/decrease repr.