On the plasticity of intelligence in adulthood and old age: Where Horn and Donaldson fail.

Challenges the critique by J. L. Horn and G. Donaldson (see PA, Vol 57:Issue 4) of the K. W. Schaie and P. B. Baltes research and writings on intelligence in adulthood and old age, contending that it seriously misrepresents Schaie's and Baltes's theoretical positions and data interpretations. It is noted that Schaie and Baltes do not reject in toto the notion of intellectual decline; within the framework of a dialectical interpretation of intelligence in adulthood and old age, they emphasize plasticity as evidenced in large interindividual differences, multidimensionality, multidirectionality, modifiability, and the joint import of age- and cohort-related determinants. When arguing for the adequacy of a fluid-crystallized model of intelligence, Horn and Donaldson's critique conveniently de-emphasizes the empirical significance of cohort effects. Contrary to a process-oriented dialectical view, the critique (assuming fairly invariant and fixed change patterns) espouses a model of adult gerontological development which Schaie and Baltes judge to be anachronistic. It is concluded that Horn and Donaldson present a reactionary critique which, if taken too seriously, is likely to inhibit much-needed progress in the field of intelligence in adulthood and old age. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)