Complexity is one of the major demands of adolescents' future life as adults. To investigate adolescents' competence development in applying problem-solving strategies in complex environments, we conducted a 2-wave longitudinal study in a sample of Finnish adolescents (11-17 years old; N = 1,959 at Time 1 and N = 1,690 at Time 2, 3 years later).…

Recent studies reveal that children can solve proportional reasoning problems presented with continuous amounts that enable intuitive strategies by around 6 years of age but have difficulties with problems presented with discrete units that tend to elicit explicit count-and-match strategies until at least 10 years of age. The current study tests…

By 3 years of age, children can solve tasks involving physical principles such as locating a ball that rolled down a ramp behind an occluder by the position of a partially visible solid wall (Berthier, DeBlois, Poirer, Novak, & Clifton, 2000; Hood, Carey, & Prasada, 2000). However, the extent to which children use physical information (the…

Dual-process theories have been proposed to explain normative and heuristic responses to reasoning and decision-making problems. Standard unitary and dual-process theories predict that normative responses should increase with age. However, research has focused recently on exceptions to this standard pattern, including developmental increases in…

Two studies were conducted to examine whether the elderly maintain the competence to solve Piagetian conservation problems. The results are discussed in terms of a distinction between competence and performance. (JMB)

This study assessed the ability of fourth, fifth, and sixth graders and college students to logically include and exclude variables when making inferences about a multivariate "natural experiment" situation. (Author/SB)

Normal elementary school children and retarded adolescents were given a problem solving task. The performance of retardates was inferior to that of normal children when mental age was controlled. (ST)

Results showed that only 32 percent of adult female shoppers in a supermarket were able to use a proportional reasoning strategy to determine which of two sizes of a common item (size ratio 2:3) was the better buy. Performance declined when the ratio was more complex. (JMB)

Examines the effects of principle of inference, relatedness of content, and mode of test presentation on the development of the conditional reasoning abilities of primary-grade children. (Author/SDH)

To evaluate prevalence of perseveration in early search, nine-month-olds were tested on both two- and three-location version of Piaget's AB task. Three principal findings emerged: (1) infants did not show systematic perservation on either location task; (2) they did demonstrate positive search skills; and (3) they searched using similiar methods…

Examines the relationship between development of logical processes required in deductive reasoning and their use by preschoolers, also considering possible explanations for children's deductive reasoning. The relationship of problem content to real-world knowledge and the sequence of presentation of problem types were found to affect the display…

Examines a model for children's strategies for inclusion tasks. Suggests that young children are not consistent in task strategies and that they display mixed response strategies. Strategies may change with development. (ET)

Presents a study of inferential problem solving abilities of 5-year-old children. Tasks involved the combination of separately acquired behavior segments in order to solve a novel problem. (BD)

Nine- to 18-month-old infants were presented with simple two-location manual search tasks involving invisible displacements of objects with sequence of displacements occurring before infants search. Results provided insights into age differences associated with development of logical search strategies, information-processing skills, and temporal…