College students were assigned to either dyadic or individual problem-solving conditions and were given a series of formal operational tasks. Dyadic subjects solved more problems during the interaction phase than did individual subjects. Among dyadic subjects, interactions were associated with problem solving and pre-to-posttest gain scores. (BC)

Administered five Piagetian tests to 180 adolescents for comparison to similar samples from 1967 and 1972. Found that today's adolescents exhibited higher levels of cognitive development than did previous cohorts. Gain varied across tasks, being very large for combinatory thought but mixed for conservation. This acceleration of cognitive…