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Dr Jaimie Krems17 November 2022

The Evolutionary Psychology Of Friendship - Dr Jaimie Krems - #553

2Frameworks
17Insights

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Frameworks in this episode

Insights & moments

The myth-busts, hot takes, explainers, and tools worth keeping.

Myth Buster· 2

Myth Buster28:30

Jealousy isn't a defect, it's an adaptive signal

Culture and even researchers frame jealousy as a vice tied to low self-esteem or immaturity. Krems pushes back: jealousy appears across cultures, eras and social species, from Spanish Mustangs to cows, dolphins and lions. If it were purely maladaptive, selection would have removed it; instead it likely serves a function, telling you not to lose someone you value.

  • Researchers have wrongly cast jealousy as a sign of low self-esteem
  • Jealousy-consistent behavior appears in horses, cows, dolphins and lions
  • Purely maladaptive traits get selected out; jealousy persisted
  • Its function: flag that a valued relationship is under threat

if it's so and solely maladaptive selection would have gotten rid of it but it's probably not so and solely maladaptive

Jaimie Krems · 30:00
#jealousy#adaptation#cross-species
Myth Buster71:30

The 'casual sex means low self-esteem' stereotype is wrong

Krems studied the pervasive belief that women (not men) who have casual sex must have low self-esteem, prevalent enough to be a TV punchline. Even when told a woman loves casual sex and is happy, participants still rate her self-esteem as lower. Crucially, the participants who hold the stereotype show no real link between their own sexual behavior and self-esteem, so the belief is robust and simply false.

  • Stereotype applies to women who have casual sex, not men
  • It persists even when the woman is described as happy and willing
  • Perceived low self-esteem cuts friendship, dating, hiring and voting odds
  • Stereotype-holders' own behavior shows no such correlation

in America people think that women but not men who have casual sex must have low self-esteem

Jaimie Krems · 72:00

it exists it's persistent it's robust and it's wrong

Jaimie Krems · 79:00
#self-esteem#casual-sex#stereotypes

Hot Take· 3

Hot Take39:30

The 'dad bod' signals a better father

Krems and Williamson unpack Mitch Brown's work suggesting male gut fat can read as a cue of being a good dad. The mechanistic account: you can spend a calorie on mating effort or parenting effort. A very attractive man can cash in on mating; a dad-bod man, with fewer mating doors open, is assumed more likely to invest that energy in parenting. The effect is small but consistent.

  • Male gut fat can cue 'good father' perceptions
  • One calorie can go to mating effort or parenting effort, not both
  • Fewer mating options implies energy redirected to family
  • The effect is small but reasonably consistent

you have one calorie you can't spend it twice you can spend it on mating effort or you can spend it on parenting effort

Jaimie Krems · 40:00
#dad-bod#parenting-effort#mate-choice
Hot Take47:00

Slut-shaming as a price-enforcement mechanism

Williamson frames slut-shaming, drawing on Geoffrey Miller, as a price-enforcement mechanism that stops any one woman from dropping the 'price' of sex below what most women want to charge. Krems adds a biological-market angle: if one woman accepts fewer resources for reproductive access, it lowers the market value of every other woman's reproductive resource.

  • Slut-shaming enforces a floor on the 'price' of sex
  • It's disproportionately enforced by women, per Williamson's observation
  • Biological market view: undercutting lowers everyone's resource value
  • Even promiscuous women don't want promiscuous women as friends

if women are voluntarily accepting fewer resources for access to their reproduction and another woman's doing that it lowers the value of my resource on…

Jaimie Krems · 47:00
#slut-shaming#biological-market#mating
Hot Take66:30

Sexual strategy can lead to religion, not just the reverse

Krems argues the causal arrow between religion and sexual strategy runs both ways. Religions tend to endorse restricted-strategy benefits: one mate, marry early, invest heavily, stay together. So people who already have restricted strategies are drawn to religion because it serves their interests. Data suggest religiosity rises during committed, sexually restricted periods and falls when people leave them.

  • Religions reward restricted-strategy behaviors
  • People with restricted strategies are drawn to religion
  • Religiosity rises in committed relationships, falls after breakups
  • The 'people get conservative with age' effect washes out controlling for number of children

people who have a certain sexual strategy get attracted to religion because it it benefits the strategy that they have

Jaimie Krems · 68:30
#religion#sexual-strategy#conservatism

Explainer· 10

Explainer01:30

Why women may have fewer, deeper friends: the allo-parenting hypothesis

Krems is candid that the field doesn't fully know why women evolved fewer, deeper friendships. Leading explanations: non-human primate evidence that a few close female friends boost a female's and her offspring's longevity, and the allo-parenting idea that the high cost of entrusting your child to the wrong person raises women's threshold for calling someone a good friend.

  • Honest uncertainty: the field doesn't have a settled answer
  • Primate data: close female friends boost female and offspring longevity
  • Allo-parenting raises the cost of choosing a bad friend
  • Patrilocality may design women to form kin-like bonds with non-kin

having just a few close female friends can increase the female's own longevity and the Health and Longevity of her Offspring

Jaimie Krems · 02:00

if you're going to put your child into the hands of somebody else that to me would suggest okay well I need to make sure…

Chris Williamson · 03:00
#alloparenting#friendship#fitness
Explainer13:30

Why reputational attacks on women are harder to refute

Krems argues the traits women are reputationally valued for, like chastity, loyalty and trustworthiness, are hidden and hard to prove, so a false accusation is nearly impossible to disprove. Men's reputational vulnerabilities, like being poor or weak, are on display and can be refuted with visible evidence such as a Rolex or a sports car.

  • Chastity and fidelity are hidden traits that can't be demonstrated
  • You can't prove how little sex you're having
  • Men can refute 'you're a bum' by showing money or status
  • Loyalty and trustworthiness are hard to assess for everyone

if a woman gains a reputation as being unfaithful or sexually promiscuous that's a really hard reputation to do away with right you can't show…

Jaimie Krems · 14:00
#reputation#intrasexual-competition#sex-differences
Explainer18:00

Attractive women attract more aggression, and more friends

Krems explains a bind: more attractive women evoke more aggression from other women because they're stronger mating competitors, yet they're also formidable allies who accumulate goodies, friends and higher salaries. That makes them simultaneously dangerous rivals and desirable friends, which complicates the simple 'attractive equals disliked' story.

  • Attractive women draw more aggression as mating competitors
  • But attractiveness also brings status, friends and resources
  • This makes attractive women both powerful allies and dangerous rivals
  • A merely promiscuous woman offers no upside, so aggression is easy

attractive women actually evoke or attract more aggression from other women

Jaimie Krems · 18:00
#attractiveness#female-aggression#intrasexual-competition
Explainer20:00

Men want higher-status friends; women can't be seen to strive

Men are happy, even eager, to befriend guys who out-compete them, because a stronger ally makes the whole group more formidable. Women face the opposite pressure: openly striving or claiming superiority ('mine's even better') gets you excluded, so women must compete to get what they want while hiding that they're competing.

  • Men prefer friends further up the hierarchy than themselves
  • A better ally strengthens the coalition, so it isn't threatening
  • Girls learn not to stand out or seem superior
  • Women face a bind: must compete but can't be seen competing toward friends

guys love being around other successful guys and they're even actually pretty big fans of being friends with guys that can out-compete them

Jaimie Krems · 20:00

they just don't want their female friends to be competitive toward them

Jaimie Krems · 22:00
#status#coalitions#sex-differences
Explainer23:00

Friend guarding: the friendship version of mate guarding

Krems introduces friend guarding as a parallel to mate guarding. Just as a partner who feels a mate slipping away may deploy cost-inflicting tactics, people guard valued friendships against poachers. The surprising twist: unlike romantic jealousy, being guarded by a friend isn't automatically hated, and can be read as a welcome cue of how much you're valued.

  • Friend guarding mirrors mate guarding, aimed at a friend not a partner
  • The traits that make a poacher scary differ between friends and mates
  • People are not universally predisposed to hate being guarded
  • A friend guarding you can read as a signal that they value you

friend guarding can look really similar to mate guarding it's just your guarding a friend instead of a mate

Jaimie Krems · 24:00
#friend-guarding#mate-guarding#jealousy
Explainer31:30

Where fat sits matters more than how much: gut vs hips

Krems describes what she believes is the first empirical study showing fat stigma tracks not just body size but fat location. Two women of identical height, weight and BMI are judged very differently: the one carrying fat in her gut is stigmatized more than the one carrying it in hips and thighs. Waist-to-hip ratio likely signals youth and future reproductive value rather than immediate fertility.

  • Fat stigma is sensitive to location, not just amount
  • Gut fat is judged more harshly than hip and thigh fat
  • Low waist-to-hip ratio likely signals youth and future reproductive value
  • Gut fat is the type linked to type 2 diabetes and heart disease

the woman who carries her fat in her gut is going to be stigmatized much more people have much less favorable views of her

Jaimie Krems · 32:30
#body-image#waist-hip-ratio#attraction
Explainer42:30

Why women dress modestly when new to a group of women

Krems presents her wardrobe research: women flexibly calibrate how much skin they show based on who they'll be around and their aggression risk. When new to a group of women they've never met, they dress more modestly to avoid being excluded or attacked. She cites Tracy Vaillancourt's study where the same woman, dressed provocatively, drew stares and insults from strangers who didn't know they were being observed.

  • Women adjust outfit modesty to context and aggression risk
  • New-to-group situations trigger the most modest dressing
  • Experiments let women pick an outfit for a women-only night
  • Vaillancourt's confederate was insulted when dressed provocatively

particularly when women are new to a group they're going to meet other women they're more likely to dress modestly so as to not be…

Jaimie Krems · 43:00
#wardrobe#female-competition#modesty
Explainer58:00

Abortion attitudes as a mating strategy, not just morality

With Martie Haselton, Krems argues opposition to abortion can function as a mating-strategy defense. Committed sexual strategists are threatened by an environment of cheap casual sex, so they benefit by restricting it. A three-bills experiment found that people who call abortion 'murder' back only the bill that punishes women, and actually oppose bills that save the same number of lives via sex ed or newborn care, suggesting the stated motive isn't the real driver.

  • Committed strategists are threatened by an atmosphere of casual sex
  • Restricting abortion, birth control and drugs reduces casual sex
  • Three bills saved equal lives; only the punitive one drew support
  • Stated 'saving lives' motive didn't predict supporting life-saving bills

the more that I think abortion is murder the more that I want to punish women for having abortions um but we actually see slight…

Jaimie Krems · 63:00
#abortion#sexual-strategy#morality
Explainer85:30

Why women's friendships are dyadic and men's are club-like

Women form intense, personalized one-to-one 'best friend forever' bonds; men's friendships are casual and group-based, easily swapped when a friend moves away. Dunbar links women's dyadic bonds to needing support after moving into a husband's community, and men's interchangeable bonds to warrior-group defense where casualties must be absorbed.

  • 85% of women have a BFF, usually another woman; men rarely do
  • Social networks stay ~70% same-sex from age 5 to 85
  • Women's bonds are personal and dyadic; men's are casual and club-like
  • Male bonds are group-based and interchangeable, fitting warrior/defense roles

for women those friendships are personalized and dyadic and very focused on the individual... men's friendship is kind of more casual... club-like

Robin Dunbar · 88:00
#friendship#gender#social-networks#bonding
Explainer79:30

A good friend helps you and doesn't help your enemy

Krems previews a cross-cultural study on what makes a good friend. The twist question: is a friend who helps you and someone you dislike better, or one who helps you but not that person? Objectively the first is twice as helpful, but in the US people rate the friend who withholds help from your enemy as the better friend. Friendship is judged super-dyadically: how a friend radiates effects onto you, including by not helping your rivals.

  • Question pits an objectively more helpful friend against a partisan one
  • US participants rate the partisan friend as the better friend
  • Friendship value includes indirect effects, like snubbing your enemies
  • 'Nice' really means 'nice to us'; a good friend is good for us

when we say somebody is nice we mean they're nice to us and when we say somebody is a glorious monster we mean they're a…

Jaimie Krems · 82:00
#friendship#superdyadic#cross-cultural

Story· 1

Story06:30

The 120-degree angle men stand at when they talk

Williamson relays a finding from Robin Dunbar's 'Friends' book: men, on average, stand at roughly a 120-degree open angle to each other when talking, while women stand comfortably front-on. The argument is that face-to-face, eye-to-eye positioning is confrontational for men, so they angle their bodies to defuse any cue of attack.

  • Men average ~120 degrees open when talking to each other
  • Front-on positioning carries a confrontational, pre-fight undertone for men
  • Women are comfortable standing fully front-on to each other
  • Once noticed, it's hard to un-see at parties

it's almost always going to be slightly open so they're going to be about 120 degrees was the average angle that was found

Chris Williamson · 07:00
#body-language#dunbar#sex-differences

Takeaway· 1

Takeaway85:00

Why friendship is hard and self-help ignores it

Krems and Williamson close on why friendship gets short shrift in personal development despite happiness research pointing to relationships first. It's hard to sell because the outcome depends on others, not just the sovereign individual. And 'friendship' is really an umbrella for ~60 challenges: figuring out what you want, finding, attracting, making, keeping and losing friends, plus super-dyadic complications.

  • Happiness research keeps returning to good relationships
  • Lacking friends is likened to smoking 15 cigarettes a day
  • Self-help avoids it because outcomes depend on others, not just you
  • 'Friendship' spans ~60 distinct challenges, none of them easy

friendship is an umbrella term for about 60 different challenges

Jaimie Krems · 86:30

we have really good theories of friendship that can tell you what to do to get people to invest in you and have a stake…

Jaimie Krems · 89:00
#friendship#happiness#personal-development