A long-running study shows that people's patterns of cognitive ability do not change much as they age.
A popular - but controversial - theory claims that as people age their cognitive skills tend to merge, in a process known as de-differentiation. This means, put simply, that verbal, mathematical and memory skills tend to average out, making the person seem less of an individual in a mental sense.

De-differentiation is the reverse of the process of mental evolution we go through as we mature from children into adults, as our mental strengths develop. In the Australian Longitudinal Study of Ageing, a group of nearly 2,000 people in different age groups were tracked with mental tests. This showed that mental differences were retained from age 72 through to age 83. In other words, the study does not support de-differentiation. You probably know your own mental strengths - a good memory, or an articulate turn of speech. According to these findings, you can continue to enjoy these strengths as you get older (and the bad news is that you cannot expect your mental weaknesses to get any better).