We contend that individual-level (“i-frame”) intervention strategies can be appropriately integrated with system-level (“s-frame”) strategies to optimize population-level behavior change. We outline instances of effective “i-frame” interventions, and how coordinated, integrated, well-resourced interventions that encompass components at both levels, and has organizational and user-group support, may optimize sustained behavior change intervention efforts, and allay practices that undermine “s-frame” components.

I contend that Kurzban et al.'s model is silent on three issues. First, the extent to which opportunity-cost computations are automatic or deliberative is unclear. Second, the role of individual differences in biasing opportunity-cost computations needs elucidating. Third, in the absence of tasks, task persistence will be indefinite, which seems unfeasible, so perhaps integration with a limited-resource account is necessary.