Foundations Of Cognitive Science

Crystallized Intelligence

Crystallized intelligence can be defined as "the extent to which a person has absorbed the content of culture."(Belsky, 1990, p. 125) It is the store of knowledge or information that a given society has accumulated over time.

Crystallized intelligence is measured by most of the verbal subtests of the Wechsler Adult Intelligence Scale (WAIS).

Crystallized intelligence is important to psychologists as it relates to the study of aging. There is ongoing intense debate among psychologists as to whether or not intelligence declines with aging. Horn (1970) hypothesized that because crystallized intelligence is based on learning and experience, it remains relatively stable over time. He claims it may even increase "as the rate at which we acquire or learn new information in the course of living balances out or exceeds the rate at which we forget." (as cited in Belsky, 1990, p. 125) On the other side of the debate, Belsky (1990) claims crystallized intelligence in fact declines with age. Why? Because, "at a certain time of life the cumulative effect of losses - of job, of health, of relationships - cause disengagement from the culture, and so forgetting finally exceeds the rate at which knowledge is acquired." (p. 125)


  1. Belsky, J. K. (1990). The psychology of aging theory, research, and interventions. Pacific Grove, CA: Brooks/Cole.
  2. Horn, J. (1970). Organization of data on life-span development of human abilities. In R. Goulet and P.B. Baltes (Eds.). Life-span developmental psychology: Research and theory. New York: Academic Press.