Dunbar's number: ~150 relationships
Anthropologist Robin Dunbar found that humans can maintain a maximum of about 150 stable social relationships due to the cognitive limits of our neocortex.
Snapshot · SOLVED with Mark Manson
How to Make Friends as an Adult, Solved
Explore episode
Nov 1, 2025
Where this was said
Introduction
At 51:24 · chapter starts 0:00
The external headwinds are numerous and mutually reinforcing. Time poverty is the most cited: longer working hours, intensive parenting norms (Jonathan Haidt's helicopter parent critique surfaces here), and increasingly packed calendars leave little room for the repeated, casual contact that friendship requires. A more mobile, job-hopping society constantly resets the proximity clock — average job tenure, once a decade, now sits under two years. Remote work privatises yet another source of daily social exposure. Third places — cafes, parks, libraries, civic clubs — have either disappeared or been monetised into status-signalling luxury venues (Soho House as the target example). Political polarisation has introduced a subtle social tax: Mark describes the exhausting calculation required before sharing any political view, and how a minority of maximally-reactive people has made everyone cautious. Robert Putnam's Bowling Alone documents this civic decline stretching back to the 1950s, predating social media entirely [1] — Drew Birnie "Technology has progressively privatised social life: the car enabled suburban retreat, TV privatised leisure, and the smartphone privatised…" 4:00:00 . Drew and Mark then discuss the inoculation counter-argument: Jonathan Haidt's cross-national data shows that countries with strong communal food and gathering cultures have been largely protected from the worst mental-health trends — not because they avoided technology, but because the in-person infrastructure remained strong enough to buffer against its effects.
People without a close friend quadrupled
The number of people reporting no close friend has quadrupled over the last 30 years, signalling a dramatic erosion of deep social bonds.
Time spent alone up 25%
The average person spends 25% more time alone than they did 20 years ago, while time spent socialising has dropped by 60% in the same period.
20% of adults lonely daily
Twenty percent of adults report feeling lonely on a daily basis, an all-time high, reflecting the severity of the modern loneliness crisis.
Darwin's Unsolved Problem: Why Do We Have Friends?
Friendship baffled Darwin so deeply he feared it could unravel his entire theory of natural selection. The answer arrived in 1980 not from biology but from a 4-line computer program called Tit for Tat — which showed that cooperation across repeated interactions is the single most evolutionarily optimal strategy.
Tit for Tat: 4 lines of code won
In Axelrod's 62-submission computer tournament, the simplest strategy — Tit for Tat, written in just 4 lines of code — outperformed all complex models by cooperating first and then mirroring the other player.
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