What is Love? Paul Eastwick on the New Science of Attraction
Keen On America
Pair bonding and human evolution
Paul outlines how enlarging brains and costly offspring favored pair bonding and cooperative parenting.
"She's a ten to me and that's the part that matters." — Paul Eastwick
If it's Valentine's Day, we must be talking about love. Paul Eastwick studies attraction and relationships at UC Davis, and his new book Bonded by Evolution takes aim at the "old science" that treated romance like a competitive market where everyone gets assigned a number. The incels, of course, ran with that research to compound their paranoia about the other sex. Eastwick says they got it wrong—and so, with the exception of Paul Eastwick, did most academics.
When two people look at the same photograph and make a hot-or-not judgment, Eastwick explains, they only agree about 65% of the time. After they've known the person for months, agreement drops to barely better than a coin flip. So there isn't any universal hierarchy of desirability. What's real is that some people will think you're an 8 and others will think you're a 3—and that quirky disagreement explains most of what happens in the science of attraction. The problem is that dating apps make everything feel like they're in a market, thereby filtering out the "slow burn" people who need time to grow on you. Eastwick's advice, therefore, is forget swiping, reboot your social networks, throw candle lit dinner parties where nobody knows each other. It's more democratic, it takes longer, and it actually works. Happy V day everyone.
About the Guest
Paul Eastwick is Professor of Psychology at UC Davis, where he studies attraction and close relationships. He is the author of Bonded by Evolution: The New Science of Love and Connection (2026) and co-host of the podcast Love Factually with Eli Finkel.
References
Concepts discussed:
● The mating market hypothesis treats attraction like an economic exchange where people are assigned desirability values and seek partners at their "level"—an idea Eastwick argues is far more limited than academics have assumed.
● Limerence is the academic term for the intense, obsessive early stage of romantic attraction—what we might call infatuation or passion.
● The Dunbar number (~150) represents the cognitive limit on stable social relationships—roughly the size of hunter-gatherer groups where our mating psychology evolved.
● Pair bonding emerged in human evolution about two million years ago as brain size increased and children required longer periods of intensive parental investment.
● Attachment theory describes the deep bonds that form when we trust someone to have our back, celebrate our successes, and support us through difficulty.
Evolution and mating:
● Human males became smaller relative to females and lost their sharp canines as women selected for men who were safe around babies—"the evolved male is the good caregiver and good dad."
● Unlike gorillas with their harem-style mating, humans shifted toward pair bonding because helpless infants with expanding brains needed investment from both parents.
● Polyamory research shows that people can form genuine attachment bonds with multiple partners—trust, wellbeing, and attachment levels match or exceed monogamous couples.
Also mentioned:
● Eli Finkel is Eastwick's co-host on the Love Factually podcast and author of The All-or-Nothing Marriage.
● When Harry Met Sally (1989) depicts "one of the most beautiful friendships on screen," according to Eastwick, and holds up well on the friends-to-lovers pathway.
● Baz Luhrmann's Romeo + Juliet (1996) was the subject of a recent Love Factually episode—"that MTV style of filmmaking" with Claire Danes and Leonardo DiCaprio.
● The incel and manosphere communities have taken 1990s attraction research and "run with it in some strange and unjustified ways."
About Keen On America
Nobody asks more awkward questions than the Anglo-American writer and filmmaker Andrew Keen. In Keen On America, Andrew brings his pointed Transatlantic wit to making sense of the United States—hosting daily interviews about the history and future of this now venerable Republic. With nearly 2,800 episodes since the show launched on TechCrunch in 2010, Keen On America is the most prolific intellectual interview show in the history of podcasting.
Chapters:
- (00:00) - Introduction
- (00:36) - Happy Valentine's Day
- (01:42) - The pressure of Valentine's Day
- (02:34) - Old science vs. new science
- (03:02) - The incel corner of the internet
- (04:05) - We've lost the art of socializing
- (05:06) - Love as a market
- (06:52) - What happens after swiping
- (08:03) - Slow burn people
- (09:07) - Twos, fives, and tens
- (10:31) - The hot-or-not experiment
- (11:33) - Is there something un-American about this?
- (13:13) - The Dunbar number and hunter-gatherers
- (14:10) - Did love exist before modernity?
- (15:07) - Passion and limerence
- (16:39) - Looking for yourself or the other?
- (18:15) - Machine learning can't predict compatibility
- (19:43) - Why we pair bond: helpless babies
- (21:30) - Men got gentler and lost their canines
- (22:52) - What polyamory tells us
- (24:36) - Gen Z and the delay of first sex
- (26:48) - Paul's love life
- (27:44) - She's a ten to me
- (28:01) - Romcoms and Love Factually
- (31:08) - Advice: reboot your social networks
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