Measures

Sensation-seeking and self-regulation were measured using Grasmick’s self-control scale, which is based on Gottfredson and Hirschi’s (1990) low self-control theory of crime. The measure acknowledges the multi-dimensional nature of self-control (Wojciechowski 2020), measuring six subdimensions in total. Two of these subdimensions have been noted to capture constructs that map to the constructs of dual systems theory (e.g., Forrest et al. 2019). Specifically, sensation-seeking was measured using the 2-item risk-seeking subscale from an adapted version of Grasmick’s self-control scale (Grasmick et al. 1993). The two items were: “Excitement and adventure are more important to me than security” and “Sometimes I do dangerous things just for the fun of it”. Item responses were recorded on a 4-point scale from 1 = false to 4 = true and summed to provide an overall sensation-seeking score with a possible range from 2–8. Self-regulation was measured using the 2-item impulse control subscale from the same adapted version of Grasmick’s self-control scale (Grasmick et al. 1993). The two items were “I often act on the spur of the moment without stopping to think” and “I often do whatever brings me pleasure here and now, even at the cost of some distant goal”. Item responses were recorded on a 4-point scale from 1 = false to 4 = true. Scores were reversed and summed to provide an overall self-regulation score, with a possible range from 2–8. Previous factors analyses in the current and other samples have supported the proposed multi-dimensional structure of Grasmick’s self-control scale and support making a distinction between the sensation-seeking and self-regulation components (Ribeaud and Eisner 2006).

Delinquency was measured using a variety score comprising responses to items describing 7 delinquent behaviors that were measured consistently across all waves included in the present study. Variety scores are considered advantageous over alternative methods of scoring delinquency (e.g., frequency-based scores) because they avoid the problem of scores being largely driven by frequent minor offences (Sweeten et al. 2013). These items referred to stealing at home, shoplifting goods worth less than 50CHF, shoplifting goods worth more than 50CHF, vehicle theft, fare dodging, vandalism, and assault. The 12-month incidence for each item was measured on a binary response format and a sum of these responses was used to create a composite score for each wave. As such, greater values on the score indicate engagement in a greater variety of delinquent behaviors, with a possible score range from 0 to 7 delinquent behaviors.