Research supported by a grant from the Defense Research Board of Canada. (DS)

Paper presented at the 48th Annual Conference of the American Occupational Therapy Association, Portland, Oregon, October 20-26, 1968. Research supported by U.S. Public Health Service Grant Number FR05357.

The processing of a transitivity task by 7-, 9-, 11-, and 13-year-old learning disabled children was studied. All Ss, regardless of age, received highest scores on tasks involving linguistic input. There was no evidence of a developmental shift from spatial into linguistic reasoning. (Author/SEW)

Among the many theories attempting to explain sex differences in spatial ability, one of the most highly researched is the X-linked recessive gene theory. This is a review of the major research done on that theory and shows the conflicting nature of the results. (Author)

Research in progress on some unresolved issues regarding the relationship of cognitive development and language acquisition is reported, especially the relationship between conservation of length and knowledge of relevant comparative dimensional adjectives. Much further investigation is recommended and possible educational implications are…

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.…

The hypothesis that overall-similarity relations structure both adults' and children's classifications of heterogeneous objects (objects that differ in a variety of ways) was supported in two experiments. When objects varied simultaneously on many dimensions, adults and children constructed classifications that maximized within-category similarity…