In our prior study the negative correlation between Topology, a behavioral measure of fluid reasoning, and adult age diminished with the increase in the level of expertise in a cognitively-demanding domain of expertise in the game of GO. The present fMRI study was designed to investigate neural substrates of Topology. The modified topology…

A developmental theory of adult intelligence is proposed called PPIK. The PPIK theory integrates intelligence as process, personality, interests, and intelligence-as-knowledge. Data from the study of knowledge structures are examined in the context of the theory and in relation to measures of content abilities. (SLD)

The generality of ability factor structure in adulthood and old age was investigated. Data were analyzed for 198 young individuals (15-32 years), 156 younger old individuals (53-68 years), and 156 older old individuals (69-91). Variables were nine tests marking three ability factors. (Author/CTM)

This article summarizes results from studies of the organization and development of cognitive abilities in adults aged 20 to 60 years old. Theories of intelligence stipulating a hierarchy of intellectual functions, with fluid and crystallized intelligence at the top, are supported. Six conclusions on age differences are offered. (Author/RD)

Responses of 241 convicts on 18 primary mental abilities were factored to explore the idea that there are organizations among visual and auditory functions that operate independently from the relation-perceiving and correlate-educing functions of fluid and crystallized intelligence. The suggested reliable common-factor functions are discussed.…