What is sexual orientation?
Why we need biology
The outline of a theory
Childhood
Characteristics of gay and straight adults
The role of sex hormones
The role of genes
The brain
The body
The older-brother effect.
Gay, straight, and the reason why : the science of sexual orientation by Simon LeVay. ISBN 9780199737673. Published by Oxford University Press in 2011. Publication and catalogue information, links to buy online and reader comments.