Cognitive abilities and aging
More than 50 years of research has consistently found that fluid reasoning (Gf) and processing speed (Gs) are extremely vulnerable to aging, whereas crystallized intelligence (Gc)—knowledge—is maintained throughout most of adult life (Cattell & Horn, 1978; Salthouse, 1985, 1996). With the advent of contemporary IQ tests grounded in CHC theory, researchers have more recently been able to assess the developmental trajectories of a wider range of cognitive abilities. This research confirms that fluid reasoning (Gf), short-term memory (Gsm), processing speed (Gs), reading comprehension (a component of Gc), quantitative knowledge (G^), math reasoning (MR), math calculation (MC), and writing abilities (Grw- Writing) all decline with age (A. S. Kaufman, Johnson, & Liu, 2008).
In contrast, large-scale studies conducted on contemporary IQ batteries have found that long-term retrieval (Glr), visual processing (Gv), auditory processing (Ga), verbal knowledge (the vocabulary and general knowledge components of Gc), academic knowledge (AK), reading abilities (Grw), oral expression (OE), and listening comprehension (LC) are maintained at least to the age of 65.
Therefore, we conclude that speed, fluid reasoning, and shortterm memory all likely decline with age and that all of these declines contribute to a possible decline in creative thinking and creative achievement.