Four distal youth developmental outcomes were included in the questionnaire: (a) behaviour, (b) school performance, (c) subjective health, and (d) well-being. In order to assess behaviour, the Strengths and Difficulties Questionnaire (SDQ) was administered . This instrument has often been used as a screening tool for behavioural disorders [36, 37], and the psychometric properties have previously been found satisfactory in a Dutch sample of non-vulnerable children and adolescents . The SDQ contains five sub-scales of five items each: hyperactivity (example item: “I am restless, I cannot stay still for long”), emotional symptoms (example item: “I worry a lot”), conduct problems (example item: “I often have temper tantrums or hot tempers”), peer problems (example item: “I have one good friend or more”), and pro-social behaviour (example item: “I am helpful if someone is hurt, upset, or feeling ill”). The items could be scored on a three-point scale: ‘not true’, ‘somewhat true’, and ‘certainly true’. Following Goodman’s procedures, a total SDQ score was calculated by using the subscales hyperactivity, emotional symptoms, conduct problems, and peer problems (T1 ? = .73; T2 ? = .72). Higher total SDQ scores reflect a higher rate of behavioural disorder. The fifth subscale, pro-social behaviour, was computed by taking the average of the five pro-social items, and higher scores reflect more pro-social behaviour. The internal consistency of the pro-social behaviour scale was marginal (T1 ? = .61; T2 ? datingranking.net/escort-directory/peoria = .67). As a self-developed indicator of school performance, youths were asked to report how their teacher was likely to evaluate their work. The five-point scale ranged from ‘bad’ to ‘excellent’. The youths’ subjective health was assessed using a question from the Short Form Health Survey (SF-36) . Both at T1 and T2, youths answered the following question “In general, how good is your health?” on a five-point scale ranging from ‘bad’ to ‘excellent’. Finally, the youths were asked to answer the following question “How are you currently feeling?” on a five-point scale ranging from ‘bad’ to ‘excellent’, as an indicator of well-being.
Proximal childhood developmental consequences
Two proximal youth developmental outcomes were included in the questionnaire: (a) self-regulation skills, and (b) sense of coherence. The self-regulation skills were assessed using the Self-Regulation of Learning Self-Report Scale . The original scale consisted of six subscales, but, to reduce the burden for the participants, four subscales were selected for this study. The selection was based on previous research that indicated that participation in sport was most strongly related to these four scales and on the relevance of these scales for the purpose of this study. All the items could be scored on a four-point scale ranging from ‘almost never’ to ‘almost always’. Example items were: “I determine how to solve a problem before I begin” (planning), “I check how well I am doing when I solve a task” (monitoring), “I concentrate fully when I do a task” (effort), and “I try to think about my strengths and weaknesses” (reflection). Scores on the subscale items were averaged, with higher values representing stronger self-regulatory skills. The internal consistency of the scales was satisfactory: planning (eight items, T1 ? = .85; T2 ? = 87), monitoring (six items, T1 ? = .78; T2 ? = .82), effort (nine items, T1 ? = .83: T1 ? = .83), and reflection (five items, T1 ? = .80; T2 ? = .88). Sense of coherence was measured using the Dutch translation of the Orientation to Life Questionnaire (SOC-13) adapted to young people . The 13 items of this scale could be scored on a five-point scale from ‘almost never’ to ‘almost always’, with the exception of two items that were positively formulated and could be scored from ‘very bad’ to ‘very good’ (T1 ? = .83; T2 ? = .84). Example items are: “How often has it happened that people who you counted on disappointed you?” and “How often do you have feelings that you’re not sure you can keep under control?” A sum score was calculated for the 13 items, with higher scores reflecting a stronger sense of coherence.
