The underachievement of gifted students is a serious problem in gifted education. Although analytic research strategies have identified many causes of underachievement, this kind of approach still needs to be complemented by synthetic research strategies. The actiotope model of giftedness, for example, suggests that the effect of educational capital on achievement is mediated by learning capital. In an empirical study with a sample of 143 gifted Spanish secondary school students, educational capital was characterized by various forms of parental involvement aimed at the learning successes of children. Learning capital was represented by two types of learning strategies: metacognitive strategies and elaboration strategies. Following the method developed by Baron and Kenny, the hypothesized mediation of learning capital between educational capital and school achievement was confirmed.