Chapter Eight
1. What explanation for homosexuality did Gunter Dorner suggest? Why is this theoretically interesting, but morally troubling, to LeVay?

2. What is the net effect of stress on sex hormones? Explain Ingeborg Ward's "prenatal stress syndrom".

3. Summarize the evidence Dorner cited for his theory, and the evidence from independent investigators like Michael Bailey. What two reasons might there be for Dorner's findings? What unexpected result did Baily find?

4. What is LeVay's explanation for the failure to find prenatal stress syndrome in human males?

Chapter Nine
5. Why is LeVay ambivalent about the genetic approach to sexual orientation?

6. Based on data from Bailey, Pillard and others, what is the relationship of the incidence of homosexuality in monozygotic and dizygotic twins?

7. What is heritability? Explain the three numbers required to calculate heritability, and the heritability range reported by Bailey.

8. Summarize and explain Dean Hammer's molecular genetic studies on sexual orientation in men. What is the simplest and most intriguing explanation for these findings?

9. Explain what linkage markers are, and how Hammer used these to locate the chromosome region where there is a highly likelihood of a gene which is involved in homosexuality.

10. What is the relevance of research reported by George Ebbers?

11. What is the trouble with the "educated guess" approach to identifying specific genes involved in sexual orientation? How will the human genome project help?

12. Xq28 does not correlate with homosexuality in women. How might this relate to the difference between homosexuality and androphillia?

13. How, ironically, might conservative Christians use an evolutionary argument against a biological theory of homosexuality? How do lay gays respond to this, and why is this response not convincing to evolutionary biologists?

14. What two simple explanations of the apparent paradox of gay genes are not very persuasive?

15. Explain two ways in which the concept of inclusive fitness does provide a persuasive explanation of the gay gene paradox (include explanation of the role of heterozygous carriers and altruistic behavior).