Human Sexuality

Simon LeVay, Ph.D. is a British-born neuroscientist turned science writer and teacher. He was educated at Cambridge University and the University of Göttingen, Germany. In 1971, he moved to the United States. He has served on the faculty of Harvard Medical School and the Salk Institute for Biological Studies, and has taught at Harvard, the University of California, and Stanford University. LeVay has authored over 40 scientific studies; the best of known of these is a 1991 report in Science that described a difference in brain structure between heterosexual and homosexual men. This study helped spark a wealth of new research on the biology of sexual orientation. LeVay is the author or coauthor of ten books, some in the area of human sexuality and others on a broader range of scientific topics. Janice Baldwin, Ph.D. is a sociologist at the University of California, Santa Barbara. She is coauthor, with her husband John Baldwin, of numerous studies and articles in the area of sexuality and sex education, as well as the textbook Behavior Principles in Everyday Life, now in its fourth edition. The Baldwins co-teach an undergraduate Human Sexuality course that is regularly voted Best Course at UCSB. They also teach an advanced seminar course on the same topic. The Baldwins have been named as Best Professors on several occasions.

1. Sexuality: Pathways to Understanding


*Here and throughout the book, information from the 2010 National Survey of Sexual Health and Behavior

*New BOX on partible paternity ("Meet My Dads")

*Economic approach to sexuality




2. Sex and Evolution


*Males and females experience different reproductive risks: data from diverse cultures

*Consensual and coercive sex among non-human primates

*New studies on the adaptive significance of sexual reproduction




3. Women's Bodies


*New BOX on genital cosmetic surgery

*Recent debate on mammography guidelines

*Data on pubic hair removal practices




4. Men's Bodies


*"Controversy" BOX on male circumcision

*Diagrams showing neonatal circumcision technique

*New information on constituents of semen and their function




5. Sex Hormones and the Menstrual Cycle


*Molecular structures of sex steroids

*Update on steroids in sports, including Caster Semenya case

*The six core symptoms of premenstrual syndrome




6. Sexual Development
View this chapter (PDF, 3.98 MB)


*BOX: An autobiographical essay by a young person with androgen insensitivity syndrome

*Updated description of molecular genetics of sex determination, with new figure

*Organizational effects of sex hormones on brain at puberty




7. Gender


*Influence of language on gender development

*New findings on the brains of transexual men and women

*"Controversy" BOX: How should we treat transgender children?




8. Attraction, Arousal, and Response
View this chapter (PDF, 2.42 MB)


*Body mass index and attractiveness: Cross-cultural studies

*New research on rape fantasies

*Rewritten BOX on beauty and culture




9. Sexual Behavior


*New survey data on prevalence of sexual behaviors

*Hewletts' research on the significance of frequent sex among the Aka

*BOX: What is "great sex?"




10. Sexual Relationships


*Influence of sex ratio on college sex culture

*What speed-dating studies tell us about flirtation

*New findings on the brain basis of falling in love




11. Fertility, Pregnancy, and Childbirth


*BOX: Myths of pregnancy

*Core precepts of preconception care

*Are home births safe? ACOG versus midwives




12. Contraception and Abortion


*New ACOG guidelines on IUDs

*New emergency contraception pill

*BOX: Does abortion traumatize women?




13. Sexuality across the Life Span


*"Breast ironing" in Cameroon

*Does marriage have a future? Contrasting views

*Great sex after 60




14. Sexual Orientation


*Anti-gay violence in Africa

*Gay teens' suicidal or thriving?

*The latest on gay marriage




15. Atypical Sexuality


*"Controversy" BOX: Should hebephilia be listed as a mental disorder in DSM-5?

*Object fetishism: I married the Eiffel tower

*Priestly sex scandal hits Philadelphia




16. Sexual Disorders


*Expanded description of techniques: sensate focus, Kegels, coital alignment

*Premature ejaculation: home remedies, sex therapy, or new drugs?

*Faked orgasms: who, when, why--and why not




17. Sexually Transmitted Diseases


*Gonorrhea: The good news (falling incidence) and the bad news (increasing drug resistance)

*Evidence for herpes transmission between outbreaks

*HIV: pre-exposure prophylaxis




18. Sexual Assault, Harassment, and Partner Violence


*BOX: Rape in wartime

*More on intimate partner violence at college

*BOX: How young men can prevent sexual violence




19. Sex as a Commodity


*BOX: New York City: The changing face of prostitution

*BOX: Portland, Oregon: Juvenile prostitutes

*"Sexting: Is it a crime?