In Study 1, 10-, 13-, and 16-year-olds were assigned to conditions in which they were instructed to think logically and provided alternative antecedents to the consequents of conditional statements. Providing alternatives improved reasoning on two uncertain logical forms, but decreased logical responding on two certain forms; logic instructions…

Examined the relationship between age and the normative/descriptive gap--the discrepancy between actual reasoning and traditional standards for reasoning. Found that middle adolescents performed closer to normative ideals than early adolescents. Factor analyses suggested that performance was based on two processing systems, analytic and heuristic…

Children and adolescents were presented with problems that contained deontic (i.e., if action p is taken, then precondition q must be met) or causal (i.e., if event p occurs, then event q will transpire) conditionals and that varied in the ease with which alternative antecedents could be activated. Results showed that inferences were linked to the…

To examine developmental differences in practical problem solving, late adolescents and young adults were presented measures of everyday problem solving that were either self-relevant or self-neutral. Results indicated young adults were more goal-defensive than adolescents; for adolescents, reasoning competence was more strongly related to ratings…

Explored self-serving biases in use of statistical "law of large numbers" (LLN) principle. Found that, on goal-enhancing and goal-neutral problems, adolescents were more prone to schema-based memory intrusions and adults were more prone to exemplar-based intrusions. Both age groups used LLN more frequently on goal-threatening than on…

Three experiments examined the role of representations in adolescents' deductive reasoning. Findings indicated that, with age, conditional reasoning improved on tasks containing permission conditional relations; reasoning fallacies increased on tasks containing causal conditional relations. Valid conditional inferences were more common on problems…

Adolescents and young adults solved reasoning problems that related to their career goals. Results indicated that subjects found goal-enhancing evidence more convincing than goal-neutral and goal-threatening evidence; statistical reasoning was more frequent on goal-threatening than goal-neutral and goal-enhancing problems; and intellectual ability…

Examined effects of motivation and intellectual ability on adolescent reasoning. Fifty adolescents were presented "scientific" evidence relevant to their religious affiliations. A manipulation designed to motivate adolescents toward greater accuracy improved overall performance. Crystallized intellectual ability was linked to absolute level of…

Ninth and 12th graders completed intellectual ability measures and engaged in reasoning about hypothetical arguments that were either consistent or inconsistent with their own theories. Results indicated that intellectual and verbal ability predicted each of several reasoning indexes. Neither ability measures nor age were related to reasoning…

The relationship between higher order reasoning and sex bias was investigated among children 7, 9 and 11 years old. Children read arguments enhancing their own or other gender, then rated argument intelligence, judged other children based on observations, and justified their arguments. Findings showed that own-gender reasoning biases declined with…

Examined scientific reasoning and self-serving reasoning biases in 5th, 8th, and 11th graders. Found that scientific reasoning improved with age. Ratings of evidence quality and written justifications yielded mixed results regarding developmental trends in reasoning biases. Theoretical beliefs regarding religion and ego-protective motivations…

Social calculations involved in assessing one's life chances were examined with 62 undergraduates. Participants showed considerable bias in their estimates, and important individual differences in bias were found. Results are discussed in terms of general adolescent phenomena such as individuation, identity, the personal fable, and cognitive…

Examined the emergence of theory-motivated reasoning biases when early and middle adolescents evaluated evidence either congruent or incongruent to their theories of social class or religion. Found that higher order scientific reasoning was used to reject theory-incongruent evidence; judgmental heuristics were used to evaluate theory-congruent…

To explore the hypothesis that domain-specific identity development predicts reasoning biases, adolescents and young adults completed measures of domain-general and domain-specific identity, epistemic regulation, and intellectual ability and evaluated arguments that either supported or threatened their occupational goals. Biases were defined as…