Differences in sociability between women and men

The most consistent gaps concern the content of exchanges: women report on average more conversations about personal states, men more shared activities. These are averages, and the two distributions overlap widely: the variation within each group is greater than the gap separating them.

Gaps in network size are smaller and vary by instrument used, which makes comparisons between surveys unreliable on that precise point. Depending on the definition chosen, close friend, confidant or mere acquaintance, the gap changes markedly in size.

An old formulation contrasts "face-to-face" relationships, based on verbal sharing, with "side-by-side" relationships, based on joint activity. It was popularised in the 1980s and remains widely cited, including well beyond the specialist journals.

That contrast is criticised as a restatement of stereotypes, and several studies show that the measures used favour one mode of expression, which mechanically produces the observed gap.

The criticism does not abolish the gap; it disputes its size and meaning. The two readings agree on at least one point: a shared activity can carry a closeness as real as a conversation, without questionnaires capturing it as well.

Closeness questionnaires often ask about the frequency of confidences, a criterion that corresponds more to one norm of expression than another. A friendship sustained by regular outings or joint projects appears less close there than it is for those who live it.

Studies using observed rather than reported behaviour find smaller gaps, which supports the hypothesis of some instrument bias.

The measured gaps vary by country, generation and social background, which is hard to reconcile with a purely dispositional explanation. Historians of friendship point out, moreover, that many nineteenth-century correspondences between men used an emotional register that today's surveys would rather attribute to women.

Comparative work finds smaller gaps in recent generations and in settings where professional contexts are more mixed, without causation being established.

Surveys find a large proportion of same-sex relationships, particularly in childhood and adolescence, where peer group segregation is one of the most robust findings in the field. Eleanor Maccoby offered a synthesis of it in 1998, under the title The Two Sexes.

In adulthood, network mixing increases and depends closely on the mixing of the contexts frequented, which links this finding to those on homophily induced by the supply of encounters. Here again, preference and opportunity remain hard to disentangle.