What causes a child to grow up gay or straight? Neuroscientist Simon LeVay summarizes a wealth of scientific evidence that points to one inescapable conclusion: Sexual orientation results primarily from an interaction between genes, sex hormones, and the cells of the developing body and brain. LeVay takes the reader on a whirlwind tour of laboratories that specialize in genetics, endocrinology, neuroscience, cognitive psychology, evolutionary psychology, and family demographics. He describes, for instance, how researchers have manipulated the sex hormone levels of animals during development, causing them to mate preferentially with animals of their own gender. In this second edition, LeVay adds a chapter on bisexuality, reviews some uncommon forms of sexuality, and considers whether there could be a biological basis for subtypes of gay people such as "butch" and "femme" lesbians.
|Publisher:||Oxford University Press|
|Product dimensions:||6.10(w) x 9.20(h) x 0.70(d)|
About the Author
Simon LeVay, PhD, has served on the faculties of Harvard Medical School and the Salk Institute for Biological Studies. He has written eleven books, including the New York Times best-seller When Science Goes Wrong (2008) and the textbook Discovering Human Sexuality (2015).
Table of Contents
Chapter 1: What Is Sexual Orientation?
Criteria for sexual orientation
Sexual orientation in men and women
Stability of sexual orientation
Prevalence of different orientations
Are there categories?
Sexual orientation across cultures
Chapter 2: Why We Need Biology
Learning theories-influence of early sexual experiences
Learning theories-gender learning
Is it a choice?
The biological alternative
Chapter 3: The Outline of a Theory
Male and female brains
Male and female behaviors
Development of sex differences in animals
Sexual partner preference in animals
Origins of variation within each sex
Relevance to human sexual orientation
Sexual orientation in nature
Chapter 4: Childhood
Development of gendered childhood traits
Childhood traits associated with adult sexual orientation: retrospective studies
Chapter 5: Characteristics of gay and straight adults
Gendered traits in adulthood
Origin of gendered traits
Sexual orientation and cognitive traits: visuospatial abilities
Personality traits: Masculinity-femininity
Other personality traits
Chapter 6: The role of sex hormones
Hormone levels in gay and straight adults
Why focus on prenatal sex hormones?
Hormone levels during development
Congenital adrenal hyperplasia
Finger length studies
The inner ear
Central auditory system
Action of sex hormones on the developing brain
Possible causes of variability in prenatal androgen levels
Chapter 7: The role of genes
Is the family clustering caused by genes?
Molecular genetics-candidate-gene studies
Genes and sexuality in fruit flies
Genes, homosexuality, and evolution
The "fertile female" hypothesis
Beneficial effects on same-sex relatives
Chapter 8: The brain
A brief tour of the brain
The hypothalamus and sexual orientation
Other brain regions
Inhibition and sexual orientation
Chapter 9: The body
Body size and shape
Trunk and limb length
Sturcture of the face
Hair whorl direction
Chapter 10: The older-brother effect
How well established is the older-brother effect?
How strong is the older-brother effect?
The older-brother effect and handedness
What causes the older-brother effect?
Chapter 11: Beyond gay and straight
Bisexuality in men
Bisexuality in women
Age preference and pedophilia
Butch-femme and top-bottom
Chapter 12: Conclusions
Sexual orientation is linked to other gendered traits
A common origin for gender-shifted traits?
The role of genes
Does the older-brother effect work through prenatal hormones?
Is there a random biological influence?
How does sexual orientation become categorical?
Unconscious processes in sexual attraction and arousal
Changes in the prevalence and nature of homosexuality
What is sexual orientation?
Sexual orientation and gender: the social fallout
Most Helpful Customer Reviews
The author has taken a lot of care to both synthesize a large quantity of scientific research and present it in a clear and organized manner. The pages are very easy to read -- the book and layout is inviting. The language is scientific but generally respectful of the LGBT community (much more so than some other science texts). The book is what it says, a primer on the science of sexual orientation. While you won't find any intense analysis going on here, you will find more than enough depth to be interesting to the scientifically minded reader and plenty of breadth as far as sexual orientation is concerned. Bisexuality is underrepresented, perhaps. Gender identity is not the key focus of the book either. But, if you are looking for a nice, thorough resource for the science of sexual orientation, this is your book!
This is a necessary book, which comes at an important time. Back in 1991, LeVay made one of they key scientific breakthroughs in understanding the dynamics of sexal orientation. Since then, he's devoted much time and energy to informing the public discourse around matters of sexuality. This book aims to play a role in that discourse¿to make sure we recognise the limits of our knowledge, and the limits of science itself.He writes with both detail and clarity. He makes the science accessible to the lay reader, but doesn't dumb it down. LeVay doesn't shy away from a key fact which may be uncomfortable to some; that, on average, aspects of the gay brain and gay behaviour tend to conform to the opposite gender. There is some basis, it seems, in stereotypes. But stereotypes only go so far. Lurking in the book is a cruial, and much more interesting observation. While sexual orientation¿especially male sexual orientation¿tends to be fixed, behaviour and personality are not. There's a wide variation in the statistics LeVay quotes. Gay men are as different from each other, as they are from their straight counterparts. And whether the mechanism is genetic, congentital, neo-natal or psychodynamic, no single theory can explain why a particular man or woman becomes gay. LeVay emphasises the importance of this fact. It would seem that there are many ways to become gay, and they produce a wide array of gay sexualities. This science reflects the subjective experience of most gay men and women. But, alas, in its fetish for finding a single "cause" for homosexuality, science has not addressed this point. In fact, science has only begun to scratch the surface. When covering the science, LeVay repeatedly has to qualify his remarks; the studies he cites have not been replicated, or confirmed, or followed up. Even his own ground-breaking work was a small study; published, it seems, as a by product of other investigations. The science of same-sex attraction, LeVay reminds us, has a long way to go.