School psychologists use intelligence and academic achievement test scores to understand individual differences in abilities that may be directed towards learning and the learning that has already occurred. To make ethical and effective decisions regarding individualized educational programs and interventions, test users must understand the…

Identity formation is a key developmental task in adolescence. Although many adolescents in modern societies face issues of identity, there are substantial individual differences in identity exploration and commitment. Little is known about the origins of these individual differences. The current study investigated the genetic and environmental…

Cook argued that the learning of a new language leads to a state of multi-competence, with the learner's mind changing in ways that go beyond the linguistic realm. The present study follows Dewaele's suggestion that multilingualism is linked to both cognitive and psychological changes. It explores one particular under-researched relationship,…