Does intelligence decline with age? Are younger employees smarter than older employees? Do older employees lack creativity and innovative ideas?
Psychology talks about two kinds of general intelligence –Fluid intelligence (Gf) and Crystallized intelligence (Gc)
Fluid intelligence is the capacity to think logically and solve problems in novel situations, independent of acquired knowledge. It is the ability to analyse novel problems, identify patterns and relationships that underpin these problems and the extrapolation of this using logic.
Crystallized intelligence is the ability to use skills, knowledge, and experience. People rely on accessing information from knowledge gathered from experience. Crystallized intelligence is one’s lifetime of intellectual achievement, as demonstrated largely through one’s vocabulary and general knowledge.
Fluid intelligence typically peaks in young adulthood and then steadily declines. Crystallized intelligence typically increases gradually, stays relatively stable across most of adulthood, and then begins to decline after age 65. So in case of older employees, while their fluid intelligence may go down, their crystallized intelligence keeps going up.
Older employees may not do well in areas where novel solutions (independent of previous knowledge) are required, but will do well where experience/accumulated knowledge is required.
Diagram below shows relation between age, fluid and crystallized intelligence.
Fluid cognitive abilities decline across adulthood (blue line gets thinner) while crystallized cognitive abilities improve (orange line gets thicker). The dependence of decision performance (green line) on these two sets of abilities varies across contexts. For decisions that require flexible learning in a new situation (fluid), older adults may be at a disadvantage (left). When decisions can be made largely based on knowledge and experience (crystallized) older adults may make better decisions than young adults (right).
The young are cognitively robust but inexperienced; the elders can draw on a lifetime of experience but are limited in some fluid cognitive abilities. While peak in middle age ( mostly populated by Gen X) is at a sweet spot where individuals have not suffered much fluid decline but also have decades of life experience. Gen X should make best use of this sweet spot in their career growth.