As with middle adulthood, fluid intelligence (processing speed, working memory, complex attention) continues to decline. Crystallized intelligence (fund of information, verbal skills, vocabulary) remains intact for much longer. This relates to the growth of wisdom discussed above. Eventually, perhaps in the ninth or tenth decade of life, crystallized intelligence also starts to decline. Although we do expect some intellectual decline with normal aging, severe intellectual decline is not a part of normal aging, but rather a symptom of dementia.