Rapid mental decline with age is largely a myth. Many of the intelligence studies that this myth were based on have been debunked. They were done in the 60s an

Rapid mental decline with age is largely a myth. Many of the intelligence studies that this myth were based on have been debunked. They were done in the 60s and compared young college students with a random sample of older people. More recent studies have shown that, barring disease, there isn't a noticeable cognitive decline until well past 65 because experience more than makes up for declining abilities. While, for most people there isn't a noticeable decline, some studies do show older people take slightly longer to make decisions, but the decisions are usually better/more accurate. However, this isn't noticeable in all but the most extreme situations (top tier competitive chess for example). Newer research shows that this extra time is probably a combination of conscious choice to trade speed for accuracy, and more available information to sort through.