10.6084/m9.figshare.3860508.v1 Abram J. van Leeuwen Abram J. van Leeuwen Ruth Mace Ruth Mace Table S1. Comparison of baseline characteristics for analysis and attrition sample. The attrition sample consists of all individuals (singleton births) in the core ALSAC sample who were alive at 1 year but not included in the analysis sample. from Coping with a changing environment: the effects of early life stress The Royal Society 2016 adolescent sexual behaviour life-history theory personality phenotypic plasticity social clustering multiple classification models Avon Longitudinal Study of Parents and Children (ALSPAC) 2016-09-27 14:15:09 Journal contribution https://rs.figshare.com/articles/journal_contribution/Table_S1_Comparison_of_baseline_characteristics_for_analysis_and_attrition_sample_The_attrition_sample_consists_of_all_individuals_singleton_births_in_the_core_ALSAC_sample_who_were_alive_at_1_year_but_not_included_in_the_analysis_sample_from_Coping_with_/3860508 Adolescent sexual behaviour may show clustering in neighbourhoods, schools and friendship networks. This study aims to assess how experience with sexual intercourse clusters across the social world of adolescents and whether predictors implicated by life-history theory or personality traits can account for its between-individual variation and social patterning. Using data on 2877 adolescents from the Avon Longitudinal Study of Parents and Children, we ran logistic multiple classification models to assess the clustering of sexual experience by approximately 17.5 years in schools, neighbourhoods and friendship networks. We examined how much clustering at particular levels could be accounted for by life-history predictors and Big Five personality factors. Sexual experience exhibited substantial clustering in friendship networks, while clustering at the level of schools and neighbourhoods was minimal, suggesting a limited role for socio-ecological influences at those levels. While life-history predictors did account for some variation in sexual experience, they did not explain clustering in friendship networks. Personality, especially extraversion, explained about a quarter of friends' similarity. After accounting for life-history factors and personality, substantial unexplained similarity among friends remained, which may reflect a tendency to associate with similar individuals or the social transmission of behavioural norms. This study examined whether experience with sexual intercourse clusters in schools, neighbourhoods and friendship networks in a sample of adolescents from a British city and tests whether factors implicated by evolutionary life-history theory, such as socioeconomic deprivation and father absence, can account for between-individual variation and the social patterning of adolescent sexual experience.