How much does your IQ decrease with age?

Research suggests that while fluid intelligence (the ability to solve new problems and think abstractly) may decline with age, crystallized intelligence (accumulated knowledge and skills) often remains stable or even improves. The decline in fluid intelligence typically begins in a person's late 20s to early 30s, but the extent of IQ decrease varies significantly among individuals. Overall, while some cognitive abilities may decline, many older adults maintain high levels of intelligence due to their accumulated experience and knowledge.