Science Vs: The Great Mysteries of Sex with Mary Roach

Podcast: Science Vs (Spotify Studios)
Air Date: March 26, 2026
Host: Wendy Zuckerman
Guest: Mary Roach, bestselling science writer, author of Bonk

Episode Overview

In this lively and candid episode, host Wendy Zuckerman delves into the science of sex with Mary Roach, acclaimed author of Bonk: The Curious Coupling of Science and Sex. Through a mix of humor, history, and hands-on research tales, the episode explores the awkward, taboo-busting, and sometimes downright bizarre lengths scientists have gone to understand sexual behavior, orgasms, and anatomy. The conversation offers both laugh-out-loud stories and insightful commentary on why sex science remains both fascinating and, at times, controversial.

Key Discussion Points & Insights

Falling in Love with Science

• Mary Roach's Journey:
  Roach reflects on viewing science as "a dragon" in high school, associating it with boring homework, only to later realize—through journalism—that science is woven into everything in life, fueling curiosity about the world.
  • Quote (Mary Roach, 03:38):
    “I equated [science] with science homework and... the textbooks I had to read. It seemed like a slog. ...But I began to realize that science is basically you. Your body, your computer, your dog, the world... It's all about following your curiosity and just sort of asking why and how.”

The Awkward Origins of Sex Science

• The taboo nature of sex research is highlighted, with early researchers like Kinsey and Masters & Johnson pushing boundaries that society and even the scientific community found shocking.
• Historical Anecdotes:

  • Penis Camera: Early sex researchers built devices to view intercourse internally, such as a camera inserted into a phallus to film inside the vagina, evincing both the creativity and the awkwardness of studying sex (05:27).

  • Kinsey’s Attic Studies: Kinsey conducted research in his attic, hiring male prostitutes to ejaculate onto carpets to debunk myths about “projectile” ejaculation.

  • Quote (Mary Roach, 09:52):
    “Kinsey didn’t even have a lab...Kinsey was using his attic. People were coming up to the attic and just, you know, the creativity was kind of amazing.”

Science Breaks Taboos—But Slowly

• Even today, many topics—like which hole is involved in intercourse or the actual mechanics of conception—are little understood due to historical reluctance for open discussion (08:39).

• The social cost for researchers studying sex is real—mockery (bathroom jokes at conferences), difficulty getting funding, and persistent hush around “down there” issues.

  • Quote (Mary Roach, 09:13):
    “People felt so uncomfortable bringing it up. Who do you ask and who do you talk to? ...Anytime you can break down a taboo like that, I think it’s a good thing.”

Female Orgasm: A Scientific Mystery

• Why Does Female Orgasm Exist?

  • The evolutionary function remains unclear; historical theories posited that uterine contractions during orgasm help "suck up" semen to aid conception.

  • Roach recounts the rich (and often ridiculous) history of trying to prove “up suck,” including bizarre experiments with artificial semen, cervical caps, and radiographs.

  • Quote (Mary Roach, 14:44):
    “They thought... contractions... were sucking up the semen, delivering it more quickly and therefore boosting the odds of conception.”

The Up-Suck Debate: Fact or Fiction?

• Repeated experiments (both historical and recent) find little evidence for contractions significantly aiding conception, though a study with six women did find a 15% increase in retention of a sperm stimulant post-orgasm—but didn’t assess pregnancy (22:56).

  • Quote (Wendy Zuckerman, 22:50):
    “In this study of only six people, they found there was more retention...if they were to orgasm...Tabloids in the UK scream: ‘Women up to 15% more likely to get pregnant if they orgasm.’”

The Science of Animal (Pig) Sex

• Roach visits Danish pig farms, learning how artificially inseminating sows with accompanying “boar-like” stimulation—snout prodding, lying atop, mammary fondling—increases farrowing rates by 6% (15:41).
• Discussion of animal arousal cues (pigs use their ears), and the parallels—and lack thereof—between human and animal sexual response (18:44).
• Memorable moment: the instructional poster, now crumbling, for optimal pig reproduction (18:19).

Candid Experiments: Sex Under the Scanner

• Mary Roach and Husband as Research Subjects (Ultrasound Study):
  Roach and her husband volunteered to have intercourse under ultrasound in a London radiology lab. The situation was deeply awkward:

  • Fluorescent lights, crisp hospital gowns, “stimulative literature” (magazine), Les Mis soundtrack, and necessary Viagra set the scene.

  • The doctor prompts: “Please make some sort of movement in and out...You can ejaculate now.” (37:13)

  • Result: The most G-rated, X-rated footage ever (“just like, boop—in and out, in and out.”)

  • Quote (Mary Roach, 36:31):
    “No, no, no, no, no [not enjoyable]. But yes, in the sense that I’m taking notes and I’m writing down what’s happening and I’m like, this is going to be so fun to write up. So I’m like the female with the cheese crumbs…”

Measuring Female Arousal: The Plethysmograph

• Roach describes participating in a study using a vaginal photoplethysmograph (a transparent “Cinderella’s tampon” that measures blood flow as a marker of arousal), revealing how women’s physiological and subjective arousal often diverge; women’s bodies may respond to a much wider range of stimuli than they consciously realize (39:20).

  • Quote (Mary Roach, 41:21):
    “There’s physiological arousal, but it’s not necessarily tied to psychological arousal...somebody’s gonna say, well, we put a little see-through device in your vagina. In fact, you were responding, you were having a good time. And you’d be like, no, I wasn’t.”

Unusual Sexual Reflexes & Anecdotes

• People are “wired very differently”—triggers for orgasm can be surprisingly mundane or inconvenient (tooth brushing, bike riding, eyebrow rubbing).
• Roach receives emails post-TED Talk from people sharing odd orgasm triggers, demonstrating the wide variety of human sexual responses (42:41–43:43).

Taboo and the Butt

• Roach reflects on the intense taboo around the anus—even affecting medical awareness (“no brown ribbons” for anal cancer).
• Taboo can be dangerous—people avoid discussing symptoms with doctors, potentially putting health at risk (44:33–47:25).

What Makes Sex Mind-blowing?

• Masters and Johnson’s research: Committed gay and lesbian couples had “the best sex” due to “gender empathy” and a high degree of mutual attentiveness—knowing from their own bodies what feels good and responding to partner cues (48:41–50:51).

  • Quote (Mary Roach, 50:17):
    “Couples who were very attuned to the reactions and the arousal of their partner and they were aroused by that arousal...There was this connection there.”

Memorable Quotes & Moments

• Cheese Crumbs:
  “Cheese crumbs spread in front of a pair of copulating rats will distract the female, but not the male.”
  – Mary Roach [12:01], quoting Kinsey

• Pig Sexual Stimulation:
  “They had found that if you sexually stimulate...while artificially inseminating her, it leads to a 6% improvement in fertility.”
  – Wendy Zuckerman [15:49]

• Ultrasound Sex Scene:
  “He offered to play some music...he goes, Oh wait, on my laptop I have the soundtrack to Les Mis.”
  – Mary Roach [35:08]

• Cinderella’s Tampon:
  “It’s a little glass tampon...measuring blood flow in the vagina...I was a subject in that study.”
  – Mary Roach [38:28]

• Taboo Dangers:
  “With any taboo, whether it’s the asshole or...something relating to sex, if somebody feels they can’t speak about it openly...they’re unhappy, they’re putting their health possibly at risk.”
  – Mary Roach [47:01]

• Best Research Paper Title:
  “Sexual intercourse as a potential cure for intractable hiccups...unattached hiccuppers could try masturbation.”
  – Mary Roach [51:28]

• Feminine Personal Trainer:
  Mary presents a vaginal weight-lifting device (“it looked like I was giving birth to a doorknob”) and recounts the Christian company founder’s perspective:
  “Good sex is a gift from God.”
  – Mary Roach [53:10–54:41]

Notable Timestamps

| Timestamp | Segment Description | |-----------|--------------------------------------------------------------------------| | 03:38 | Mary Roach discusses falling in love with science | | 05:27 | Early sex research: penis cameras and awkward labs | | 09:52 | Kinsey’s attic studies and myth-busting | | 14:44 | Theories about female orgasm’s evolutionary function | | 15:41 | Pig insemination research and (human/animal) sexual response parallels | | 22:50 | New “up suck” study and media exaggeration of results | | 32:06 | Roach and husband’s experience as sex research subjects (ultrasound) | | 38:28 | Roach describes the vaginal plethysmograph | | 41:21 | Dissociation of physiological/psychological arousal in women | | 42:41 | Unusual orgasm triggers | | 44:33 | Taboo, the anus, and medical consequences | | 48:41 | What “mind-rippling sex” research actually reveals | | 51:28 | Funniest sex research paper: sex as a cure for hiccups | | 53:10 | The Feminine Personal Trainer: vaginal weight-lifting device |

Original Tone and Approach

Mary Roach’s characteristic wit and curiosity permeate the episode, with Wendy Zuckerman matching her irreverence and humor. They discuss taboo subjects with frankness and warmth, seamlessly blending scientific rigor with comedic storytelling. Memorable stories, awkward research setups, and an unabashed embrace of all things bodily make this episode a uniquely engaging—and educational—listen.

Conclusion

This episode serves both as a fascinating primer on the history and current state of sex research and a broader meditation on why talking about sex—and the messiness of bodily science—matters. With Mary Roach’s trademark humor, the podcast tackles taboos, celebrates scientific curiosity, and reminds listeners that the best sex, scientifically, involves empathy, communication, and a willingness to ask awkward questions—whether in the lab, the bedroom, or the pig barn.