King explains how paleontologist Stephen Jay Gould popularized the idea that female orgasm is a functionless 'byproduct,' borrowing his own 'spandrels' architecture metaphor — except the structures he meant aren't even called spandrels, they're pendentives, and they're structurally integral, not decorative byproducts.

Gould's byproduct theory framed the clitoris as vestigial, like a male nipple
Gould was politically opposed to applying evolutionary theory to humans, fearing it implied fascism
Elizabeth Lloyd, whose book started King's interest, was Gould's protégé
Gould's famous 'spandrels' architectural analogy is itself wrong — the structures are called pendentives and are structurally integral

“Oh for [expletive] sake. Right. Okay. So, I'm wrong twice.”
Chris Williamson · 08:00

“He's done a huge amount of damage in the literature because people just sort of dismiss adaptationist ideas.”
Robert King · 08:00

#evolutionary-biology#stephen-jay-gould#byproduct-theory

Myth Buster08:30

The Clitoris Is Not a 'Male Nipple' — It's 4 Inches Long

King physically demonstrates that the clitoris is nothing like the small, externally-visible organ described by 1970s theorists such as Donald Symons. It's roughly four inches long, mostly internal, has its own duct network and a dedicated somatosensory cortex region.

1970s theory described the clitoris as small, external, and functionless like a male nipple
Actual clitoris is about 4 inches long, mostly internal, with ducts and multiple innervation
It has its own dedicated area in the brain's somatosensory cortex, unlike male nipples

“It's about 4 in long. Most of it is internal...it's got its own somatosensory cortex associated with it in the brain, and none of those…”
Robert King · 09:00

#anatomy#clitoris#myth-busting

Myth Buster77:00

'Locker Room Talk' Is a Myth — Men Don't Discuss Their Sex Lives

Both King and Chris push back on the assumption, highlighted by the Trump 'grab them' controversy, that men routinely discuss their sex lives with friends in explicit detail. Both report that in their real experience, men rarely discuss specifics about their partners, and women likely talk about sex far more than men do.

Popular belief holds men openly discuss sexual conquests as 'locker room talk'
Both guest and host say this doesn't match their real-world experience among men
Men who do boast are generally seen negatively by other men, not admired
Both agree women likely discuss sex among themselves far more than men do

“Guys don't sit around and talk about their sex lives in that sort of a way.”
Chris Williamson · 77:30

“I have never heard that kind of talk. Maybe I'm going into the wrong locker rooms.”
Robert King · 78:00

#male-psychology#myth-busting#culture

Hot Take· 1

Hot Take81:30

Violent Porn Is More Popular Among Women Than Men — Everywhere

King states that porn featuring violence against women is more popular among female viewers than male viewers, and this rate holds roughly constant across cultures worldwide, uncorrelated with how women are actually treated in those societies — a fact he notes is uncomfortable to state given how it's often misused.

Porn depicting violence against women is watched more by women than men
The rate is roughly consistent globally, regardless of women's real-world treatment in that culture
King notes reluctance to share the fact because it's often seized on by misogynists

“Porn featuring violence against women is also extremely popular among women. It is far more popular among women than men.”
Robert King · 81:30

“Fantasy life isn't always politically correct.”
Robert King · 81:30

#fantasy#porn#female-sexuality

Explainer· 8

Explainer02:30

Why Masters & Johnson's Lab Sex Research Was Flawed

King contrasts Masters and Johnson's famous 1960s lab study — which used a camera-equipped glass tube nicknamed 'Ulysses' on masturbating women to conclude female orgasm has no function — with the more revealing at-home research of British couple the Foxes, who measured real intercourse and found oxytocin-driven pressure changes linked to fertility.

Masters & Johnson had roughly six women masturbate in a lab with a camera-equipped glass tube called 'Ulysses'
That study became the foundation for claiming female orgasm has no function
The Foxes, a married doctor couple, measured pressure and oxytocin changes during real sex at home in the 1970s
Their work, later expanded by Ludwig Wilt's team, found a mechanism linking orgasm to fertility

“Genuinely that was the platform on which they based the whole idea that female orgasm didn't really have any function.”
Robert King · 03:00

#sex-research#research-methods#oxytocin

Explainer15:00

Oxytocin's Real Origin Isn't Bonding — It's Milk Production

King explains that oxytocin's evolutionary origin is lactation, not pair-bonding as commonly assumed. As mammals evolved needier offspring, the same hormone got repurposed for mother-infant bonding and, later, adult pair-bonding — Freud, King argues, had the causal order backwards.

Oxytocin phylogenetically originates as the hormone driving milk production in mammals
It was later co-opted for mother-infant bonding, especially in species with needy ('altricial') young
Human babies need the most care of any mammal, driving strong oxytocin-based bonding
King argues Freud had it backwards — nurturing instinct is primary, sexual pair-bonding is the overspill

“It looks like nature was just lazy...the primary instinct was bonding with offspring, and some of that just overspilled into keeping a guy around as…”
Robert King · 16:00

#oxytocin#evolutionary-biology#pair-bonding

Explainer17:00

The Moon Cup Study: Orgasm Cuts Sperm 'Backflow' by 15-20%

King describes his 2016 study using a menstrual cup to measure 'backflow' — fluid ejected from the reproductive tract up to an hour after sex — finding 15-20% less backflow when the woman had an orgasm, offering direct physical evidence for the fertility function of female orgasm.

'Backflow' is fluid the vagina ejects up to an hour after sex
Researchers injected sperm-like material, used a moon cup to collect backflow, and measured post-orgasm vs non-orgasm results
15-20% less material came out when the woman had an orgasm
Builds on earlier Fox and Wilt team research measuring uterine pressure changes directly

“15 to 20% less comes out if she's had an orgasm.”
Robert King · 18:00

#fertility#research#sperm-transport

Explainer21:00

Surface vs. Deep: The Two Categories of Female Orgasm

King's research team asked women to describe their orgasms in detail and found they clustered into two broad types — surface orgasms that tend to be more intense, and deep, penetration-associated orgasms linked to oxytocin markers like breath apnea and feelings of trust. Neither is framed as 'better.'

Team deliberately avoided the old 'clitoral vs vaginal' Freudian framing
Surface orgasms tend to be more intense
Deep orgasms are associated with oxytocin markers: breath apnea, floaty feelings, trust
Researchers explicitly rejected the idea that one type is more 'mature' or healthier

“There are some neo-Freudian scholars who want to argue that certain orgasms are more mature than others...we weren't going down that route.”
Robert King · 22:30

#female-orgasm#typology#oxytocin

Explainer24:30

The Four Biggest Predictors of Female Orgasm

King's research identified partner smell as the single largest predictor of female orgasm — a likely signal of genetic compatibility — alongside sexual dominance, considerateness, and penetrative vigor. Notably, male attractiveness, muscularity, height, and finances showed no predictive effect.

Attractive partner smell was the single largest effect size, suggesting genetic compatibility signaling
Sexual dominance combined with considerateness were both predictive
Penetrative 'vigor' mattered
Male finances, height, and general muscularity showed no measurable predictive effect

“It looks like people want somebody who is sexually dominant but also considerate, nice smelling, pays close attention, and provides deep penetration. Those would be…”
Robert King · 25:30

#female-orgasm#attraction#research-findings

Explainer39:30

Why Women Fake Orgasms — It's a Signal, Not Just Politeness

King argues faking orgasm isn't simply about sparing a partner's feelings — it functions as a signal, similar to faked laughter, that can be voiced or unvoiced and detected acoustically. Faking can signal fertility or investment worthiness to the partner, or relationship status to onlookers.

Faked laughter has detectable acoustic differences (voiced fakes are easier to spot) — King wants to apply similar analysis to orgasm sounds
Faking can signal to the male partner that he's got a good chance of impregnating her, encouraging investment
Faking can also signal to bystanders that 'this guy is attached to me'
References a planned collaboration with laughter researcher Athena Aktipis, interrupted by COVID

“They don't take us to the...why men are interested in it as a signal.”
Robert King · 40:30

#faking-orgasm#signaling#evolutionary-psychology

Explainer44:30

The Recurring 'Anonymous Woman' Dark Romance Plot

King identifies a pattern repeating roughly once a generation — an anonymously-published book by a woman featuring a sexually dominant male love interest with BDSM elements (Story of O, Nine and a Half Weeks, Fifty Shades of Grey), each sparking outrage about 'the patriarchy,' then revealed to be female-authored and adapted into hit films women bring their partners to see.

Recurring template: anonymous female author, dominant male lead (often named 'Mr. Grey' or unnamed), strong BDSM themes
Examples include Story of O, Nine and a Half Weeks, Secretary, Fifty Shades of Grey
Each cycle sparks 'patriarchy' backlash before the author is revealed as a woman
Successful film adaptations draw women who bring male partners, urging them to 'be a bit more like that'

“We just keep doing this to ourselves as a species...a woman comes out and she goes, 'No, I wrote this.'”
Robert King · 45:30

#female-fantasy#dark-romance#culture

Explainer70:00

Why Women Can Orgasm Multiple Times: A Signaling Theory

King offers a speculative evolutionary explanation for female multiple orgasm: early in a relationship, frequent orgasms may function to keep a male partner highly invested and having lots of sex, signaling fertility potential, before naturally tapering off once pregnancy is more assured.

Frequent orgasm early in courtship may signal strong investment potential to the male partner
This encourages the male to have more sex, increasing conception odds
The pattern may taper once the relationship stabilizes, so the male doesn't continually pester for sex
King is explicit this is speculative — the mechanism isn't fully known

“We don't know. But it would be great to know.”
Robert King · 70:30

#multiple-orgasm#evolutionary-theory#mating-strategy

Story· 5

Story00:00

From School Teacher to Female Orgasm Researcher

King explains how a chance holiday read of Elizabeth Lloyd's book claiming female orgasm has no evolutionary function sent him from 20 years of school teaching into evolutionary biology research, after noticing two rival scientific traditions studying human sexuality.

Read Elizabeth Lloyd's book on holiday in Thailand claiming female orgasm has no function
Discovered two distinct scientific traditions studying female sexuality — one dismissive, one functional
Noticed many orgasm researchers weren't studying real-world sex, just lab settings

“The book told me that female orgasm did nothing, had no function...to say I was surprised would be an understatement.”
Robert King · 00:30

#evolutionary-biology#female-orgasm#career-change

Story32:30

'Venting': The Gossip Disguised as Compassion

Chris explains 'venting' — a covert form of female intrasexual competition where expressing 'concern' about another woman's sex life ('I'm just worried about her') simultaneously spreads gossip, signals moral superiority, and derogates a rival, all while maintaining plausible deniability.

Venting frames gossip about a rival's sex life as compassionate concern
It signals the speaker's own moral/purity positioning while denigrating a rival
Provides deniability if confronted ('I was just worried about you')
King notes men are frequently oblivious to this dynamic

“Venting is gossip disguised as compassion.”
Chris Williamson · 33:00

“It just goes past us. We're absolutely blind to it. We're like the kid from the sixth sense but in reverse.”
Chris Williamson · 34:00

#intrasexual-competition#gossip#female-psychology

Story36:00

Study: Female Teammates Show Less Affection Than Male Rivals

King cites a study finding that female basketball players on the same team display less physical affection toward each other than male basketball players show toward opponents on rival teams — a striking marker of underlying female intrasexual competition even within cooperative team settings.

Same-team female basketball players show less physical affection to teammates
Opposing-team male basketball players show more physical affection to rivals than the female teammates show each other
A colleague of King's, a former national-level player, confirmed the pattern from direct experience

“Female female basketball players on the same team show less physical affection to each other than male basketball players on opposite teams.”
Robert King · 36:30

#intrasexual-competition#research#sports

Story47:30

Chris's Secret Past as a Dark Romance Cover Model

Chris reveals he spent summers from age 26 to 32 as a cover model for dark romance novels, flown to US book conventions because publishers found having the model present boosted book sales enough to cover his flights and pay. He recounts noticing 'golden retriever husband' cover models — an attempt to sanitize the dominant-male archetype — that didn't sell as well.

Chris was a cover model for dark romance books, flown to US fairs and conventions for signings
Publishers profited because having the model present sold enough extra books to cover costs
'Golden retriever/cinnamon roll husband' models were a post-#MeToo attempt to soften the dominant male archetype
Those softer models reportedly didn't sell as well

“I spent every summer from the age of 26 to about 32 traveling to America because I was a cover model for dark romance books.”
Chris Williamson · 48:00

#dark-romance#personal-story#publishing

Story82:00

The Dark Tangent: Spree Killers and the Women Who Fetishize Them

King describes a side research project on spree killers — finding two distinct types: older 'family controllers' vs. younger school-shooter types — that led to studying hybristophilia, women who fetishize killers, uncovering a small subset who produce explicit erotic material glorifying real killers' violence, distinct from women simply attracted to 'bad boy' celebrities.

Spree killers split into two non-overlapping types: older family controllers and younger, mentally-ill school-shooter types
A PhD student's follow-up study examined hybristophiles — women who fetishize killers
Most such fans didn't distinguish killers from other 'bad boy' celebrities in their fan material
A smaller, persistent subgroup produced violent erotic material focused explicitly on victims' pain, openly desiring to join in

“We need to stop having sex with the psychopaths. All of us.”
Robert King · 84:00

#spree-killers#hybristophilia#dark-psychology

Q&A· 1

Q&A58:00

Girth Beats Length, According to King's Data

Asked directly whether length or girth matters more for female pleasure, King says his research found women prize girth more — consistent with the anatomy of the clitoral glans, which becomes engorged and responds to pressure and tension from girth rather than depth.

Women in King's surveys rated girth as more important than length
This aligns with clitoral anatomy — the glans becomes engorged and responds to tension and pressure
Women generally need more, and often more internal, arousal buildup than men before intercourse

“We asked women about girth and girth was the thing that they prized the most.”
Robert King · 58:00

#anatomy#female-orgasm#sexual-preference

Tool· 1

Tool87:00

Book: Naturally Selective by Robert King

King's own book, 'Naturally Selective,' covers the full case for the adaptive function of female orgasm, including detailed chapters on anatomy, oxytocin mechanisms, and why he disputes the 'obstetric arms race' theory of penis size. He also points listeners to his academia.edu page for published papers.

Book title: 'Naturally Selective' by Robert King
Covers clitoral anatomy, oxytocin, orgasm typology, and critiques of rival theories
King has no social media presence; academic papers available via academia.edu

“I've got the book. It's called Naturally Selective.”
Robert King · 87:30

#book-recommendation#female-orgasm#guest-resources

Takeaway· 1

Takeaway65:30

Nobody Has Studied Whether Birth Control Reduces Orgasms

King flags a striking research gap: despite decades of hormonal birth control use starting often before a woman's first sexual experience, no study has directly tested whether it affects orgasm frequency or sensation — even though it's known to change who women find attractive, and most sex research historically excludes female subjects entirely.

Research shows hormonal birth control changes who women find attractive, but its effect on orgasm hasn't been studied
Many women start birth control before ever having sex, shaping their entire sexual 'baseline' unknowingly
Referenced book: 'This Is Your Brain on Birth Control' by Sarah Hill
General pattern: sex and behavioral research, even on rats, has often excluded female subjects

“This massive experiment we've done on a huge amount of the population without an awful lot of control on it.”
Chris Williamson · 67:00

“I would be very surprised if it doesn't [affect orgasm], and I think it's a real gap in the data.”
Robert King · 66:00

#birth-control#research-gap#hormones

Frameworks in this episode

Ecological Validity Evidence Stack

Participant-Led Construct Discovery

Signal Decomposition Lens

Insights & moments

⚡Myth Buster· 3

Stephen Jay Gould's 'Spandrel' Theory of Orgasm Was Wrong (Twice Over)