Pitcairn Island: fertility and population growth, 1790-1856.

The hybrid English-Tahitian community which lived on Pitcairn Island between 1790 and 1856 exhibited a high population growth (3% overall). Unlike some other isolated groups, they did not live long lives (expectation of life at birth was 50.4 years overall for both sexes combined), but infant mortality, at 5.5% of births is lower than might have been expected. The level of marital fertility on Pitcairn was extremely high, higher even than for the Hutterites. Although births outside marriage were uncommon, brides were frequently pregnant at marriage. Age at first marriage changed markedly in response to changes in the community. There is some evidence that premarital sex became more frequent, possibly as an adjustment to Tahitian behavioural norms within the community's English religious ethic.