Why meeting people gets harder after thirty

Work on tie formation identifies three favourable conditions: repetition of encounters, their unchosen character, and a duration long enough for informal exchange to occur. The study by Leon Festinger, Stanley Schachter and Kurt Back of a student housing complex, published in 1950, already showed the weight of mere residential proximity in the formation of friendships.

School, study and first jobs combine all three. Few adult contexts still do, and those that do, regular activities and voluntary commitments, presuppose a deliberate enrolment.

Surveys on the origin of relationships find a declining share of relationships formed with age, and a concentration of active relationships around those born before thirty.

That concentration is more marked among people whose professional context is stable and homogeneous, which echoes the findings on network turnover. It does not mean an impoverished network: long-standing relationships simply occupy the place that new ones would occupy elsewhere.

Entering a relationship in adulthood requires an explicit initiative, whereas youth contexts produced relationships without any step being necessary. Jeffrey Hall estimated in 2019 that moving from acquaintance to friendship takes a considerable amount of time spent together, which constrained contexts supplied without anyone counting it.

Work on perceived social competence finds that this initiative is seen as costly and risky, including by people who experience no difficulty in constrained contexts.

The cost also lies in ambiguity. In a constrained context, seeing someone again requires no justification; in adulthood, suggesting a second meeting exposes one to refusal, and that exposure may be enough to discourage the initiative.

Several experimental studies on interactions with strangers, notably by Nicholas Epley and Juliana Schroeder published in 2014, find that participants anticipate less pleasant interactions than they actually are.

That gap between anticipation and experience is measured in brief contexts, transport or waiting rooms. Its transposition to the formation of a lasting relationship has not been established. A related result, described in 2018 by Erica Boothby and colleagues as the liking gap, shows that after a first conversation people underestimate how much the other person enjoyed it.

The difficulty stems from a structure of opportunities, not from a lost skill. Work on proximity and on the composition of places indicates this convergently. Nor does it carry normative weight: many people are not looking for new relationships, and the finding describes a situation, not a lack.

That is also why arrangements recreating regular contexts, rather than one-off encounters, obtain clearer results in the available evaluations.