Sexploring Human Sexuality

The Indy interviews Dr. Justin Lehmiller

Dr. Justin Lehmiller is a Professor in the Department of Psychology at Harvard. Dr. Lehmiller conducts research on secret relationships, prejudice and stigma, sexual orientation, and friends with benefits. His website,, was created to share knowledge acquired from scientific studies, rather than personal experience, about the science of sex, love, and relationships. His current project is a book entitled The Psychology of Human Sexuality.

AM: Why did you decide to study the psychology of human sexuality?
JL: I stumbled into this field by accident. Honestly, when I was an undergraduate student, I had no idea that you could even pursue a career in sex research. However, everything changed in the course of pursuing my PhD in social psychology at Purdue University. One semester, I was assigned to serve as a teaching assistant for a Human Sexuality course. My first response was, “Wait—you can take a class on this?” Needless to say, it was an incredibly eye-opening experience. Not only was it just about the most fun I had ever had in a classroom, but I learned so much practical information that I had never heard anywhere else. At the same time, I was very disappointed that I had not learned any of it sooner. This experience stimulated a desire to share this information with as many people as I possibly could and to try and contribute to our knowledge base in this incredibly understudied area through research. Since then, I have evolved into a full-fledged sex educator and researcher and I couldn’t imagine doing anything else with my life.

AM: Do you think it’s important to celebrate one’s sexuality? If so, why?
JL: I don’t know if “celebrate” is necessarily the word I would choose here, but I would argue that it is important to acknowledge and learn to be comfortable with your sexuality, whatever it may be. We know from research that when people try to repress or change their sexuality, the end result can be psychologically damaging, such as in the case of so-called “reparative therapy,” in which individuals try to change a gay or lesbian orientation to heterosexual. The key is to learn to be happy with who you are and to find a healthy sexual outlet based upon the principles of mutual consent, communication, and safety. It’s also important to recognize that there isn’t necessarily anything wrong with you if you don’t desire sex—some people are asexual and are perfectly content without sex in their lives.

AM: What are the most interesting/ useful tips you discovered led to the most pleasure from sexual encounters?
JL: All of us have brains and bodies that are a little different, so it’s impossible to say that there’s any one thing that is guaranteed to enhance sexual pleasure for everyone. The best thing you can do is to communicate with your partner and be willing to try new things that will keep your relationship exciting. Many sexual problems stem from a lack of intimacy, poor communication, and the tendency to fall into ruts and routines. It certainly takes a bit of effort, but you’re likely to have a much more satisfying sex life if you’re willing to share your desires and fantasies with your partner and are open to trying new sexual positions, settings, and acts.

AM: What are the most common myths associated with sexuality that have been proven wrong?
JL: How much time do you have? There are so many that it’s hard to make a short list. For starters, it is a myth that the key to sexual pleasure among heterosexual women is having a partner with a large penis. The reality is that most heterosexual women say that penis size makes no difference in their likelihood of reaching orgasm and that it is clitoral stimulation, not deep penetration that typically leads to climax. Another myth is that gay men are inherently more promiscuous than straight men. Research finds that gay and straight men have about equally high sex drives, and if you exclude the outliers, most of them report having pretty similar numbers of sexual partners. Other myths include the idea that there’s no such thing as male bisexuality, that porn causes brain damage, and that oysters are an aphrodisiac. Because there are so many persistent myths about sex and sexuality, I started a blog called The Psychology of Human Sexuality with the goal of debunking them and providing the public with factual, science-based information about sex.

AM: What is the weirdest fact you learned from a study or from research regarding sexual intercourse?
JL: One of the most unusual studies I ever read about involved heterosexual men who were assigned to watch one of two different porn clips: a video featuring two men having sex with the same woman, or a video of three women together. After watching the video, researchers collected sperm samples from the men. The guys who watched the video of two men and one woman produced ejaculate that contained more active sperm than the guys who watched the all-female video. Some have speculated that this is evidence of so-called “sperm competition” among men, or the idea that when men compete for access to the same mate, their sperm compete with each other in order to increase their chances of fertilization.