Our mental functions do not necessarily get worse as we age, but they certainly change. As it ages the human mind, like the human body, loses some of its agility and quickness of response, but problem-solving skills and accuracy remain remarkably constant. Older people fare badly on conventional IQ tests because of the large amount of categories such as verbal, numerical and abstract reasoning tests. But if the number of tests are reduced from the usual 11 to only six, older prople's performance comes to equal that of young people in their prime.