The three components of intelligence: Evolutionary specialization in mental abilities

A biological theory of intelligence is presented. This theory is based on information-theoretical model of hemispheric differences. This theory bases the chunking theory of Miller (1956) on the analytical-synthetical hemispheric dichotomy of Levy-Agresti & Sperry (1968). Thus all the intellectual abilities comprise three basic components: The analytical ability of the left hemisphere, the synthetical ability of the right one, and the efficiency of the interhemispheric commissures, which may underly the factor g of general intelligence. The left- and right-hemispheric mechanisms produce different quantities of heat. Therefore different climatic conditions enhanced the evolution of different hemispheric mechanisms in different ethnical groups, thus different cognitive styles might have evolved. It is suggested that the visual-spatial factor of intelligence may be misinterpreted.