INTELLIGENCE AND SAVANT SYNDROME - IS THE WHOLE GREATER-THAN THE SUM OF THE FRAGMENTS

An adequate theory of intelligence must provide an account for individ ual variation in specific cognitive abilities but also for the common variance between these that results in a general factor. However, it m ust also be capable for providing an account of savant syndrome: rare individuals who display high levels of skill beyond the accomplishment s of most people, yet who have low IQs. On the basis of recent researc h, two characteristics of savant performance are identified; the first is soundly functioning long-term memory that is narrowly focused and the second is a specific aptitude; that is, memory and cognitive proce sses dedicated to a specific ability. It is concluded that savant skil ls are not intelligent and that Gardner's (1983) theory of multiple in telligences fails by overstating the relevance of savant skills and be cause it disregards clear psychometric evidence for a general factor. Vernon's (1971) hierarchical model fails because it cannot accommodate high levels of cognitive skill, independent from general intelligence . Evaluation of the Horn-Cattell model (Horn, 1987), Anderson's (1992) process theory, and Detterman's (1982, 1986) system theory finds that each can accommodate some aspects of savant syndrome but cannot provi de a full account. An integration of the Anderson and Detterman models is suggested, which overcomes the reliance of the former on a unitary construct to explain a general factor and extends the latter to inclu de specific aptitudes.