Does variability increase with age? An archival study of cognitive measures

Area of Science:

• Gerontology
• Cognitive Psychology
• Psychology of Aging

Background:

• A common assertion suggests older individuals exhibit greater variability than younger ones.
• Published data have not consistently supported this claim regarding cognitive functions.

Purpose of the Study:

• To directly investigate the assertion of increased variability in older adults.
• To compare variability across reaction time, memory, and intelligence measures between age groups.

Main Methods:

• Analysis of published studies from "Psychology and Aging" and "Journal of Gerontology" (1986-1990).
• Calculation of coefficients of variability for reaction time (RT), memory, and intelligence data.
• Comparison of variability between younger and older participant groups.

Main Results:

• Older participants demonstrated greater variability in reaction time (RT).
• Increased variability was observed in older adults for memory and fluid intelligence measures.
• No significant difference in variability was found for crystallized intelligence between age groups.

Conclusions:

• The assertion of greater variability in older adults is supported for specific cognitive domains like RT, memory, and fluid intelligence.
• Crystallized intelligence appears to be an exception, showing similar variability across age groups.
• Further research is needed to fully understand age-related differences in cognitive variability.