A longitudinal study of the development and decline of intelligence shows that human intelligence generally reaches its peak around the age of 20, and then gradually begins to decline. A 10% decrease at age 50 is approximately equivalent to the intelligence of a 16-year-old, a 20% decrease at the age of 60 is approximately equivalent to the intelligence of a 12-year-old, and a 30% decrease at the age of 70 is approximately equivalent to the intelligence of a 10-year-old. However, there are individual differences, functional differences and quality differences in intelligence itself. The WAIS Adult Intelligence Scale was used to test the elderly. The results showed that the motor (or non-verbal) intelligence of the elderly declined significantly. If the decline rate is based on the age of 60-64, then by the age of 70-74 It dropped by 25.6% at the age of 80-84, and dropped by 40.7% at the age of 80-84. Relatively speaking, verbal intelligence remained relatively good after the age of 60, and did not decline significantly until the age of 80-84. According to the theory of American psychologist K.B. Cattell, human intelligence can be divided into two types: fluid intelligence (GF) and crystallized intelligence (Grystallizedlintelligence, GC). Specifically, the former uses The level of intelligence measured by the intelligence test with indefinite answers. The infinitive questions represent some novel and varied situations. The subjects must adapt to the situation and use image thinking to solve the problem. The level of fluid intelligence is mainly related to the development of individual neurophysiological functions. In the elderly, fluid intelligence is greatly affected due to degenerative changes in brain nerve function. The so-called crystallized intelligence refers to the level of intelligence measured by intelligence tests using fixed-answer questions. The fixed-answer questions represent the memory, identification and understanding of some factual information, and do not require the need to improvise to solve problems. The level of crystallized intelligence is closely related to the amount of individual knowledge, the level of education and learning opportunities, and abstract thinking. The elderly have rich experiences and extensive experiences throughout their lives, so their crystallized intelligence is better maintained. According to research, fluid intelligence test scores decrease by 3.75% every 10 years as age increases, while crystallized intelligence increases by 3.64%.
Someone has conducted an age statistical analysis on celebrities in various fields such as natural sciences, humanities, social sciences, literature, art, music, etc. The results show that the fields with the largest number of people who have produced achievements after the age of 60 range from high to The lowest order is: philosophy, medicine, fine arts, literature, natural science, etc. It can be seen that fields that are closely related to life experience and rich experience will bloom late.
Many scholars believe that in the past, the cross-sectional method (that is, comparing the test scores of subjects of various age groups) was used to study changes in human intelligence, and they believed that the intelligence of the elderly declines with age. In fact, this is Inaccurate conclusion. Because this method easily confuses the impact of age factors and population factors on intelligence. In fact, people born in different generations can have very different life experiences and educational opportunities, and this kind of social history and educational opportunities can be very different. The impact of differences on intelligence is even greater than the impact of age factors. In other words, the intelligence of the elderly in the test is not as good as that of the young. This does not necessarily reflect only the difference in age, but may also include the influence of factors such as life experience and education. In fact, if the old man himself compares the present with the past, his mental decline is not obvious. Using a sequential method that combines cross-sectional and longitudinal methods to study changes in intelligence, the results show that it is unscientific to say that the intelligence of the elderly declines with age. On the contrary, the intelligence of the elderly still has great plasticity. Someone conducted educational training on 30 elderly people with an average age of 69 eight times within a month. The results showed that their liquid intelligence gradually increased with the number of training sessions. Graphic relationship training for 58 elderly people with an average age of 70 can also significantly improve the performance of the elderly on the liquid intelligence test. It can be seen that living to old age and learning can improve the intellectual level of the elderly. Psychologists Baltes and Willis put forward a new view, believing that throughout the entire life course of a person, the actual application and performance of work achievements at each age stage is only the maximum potential. It is just a part of intelligence. After learning and training, the potential preserved intelligence can be transformed into using intelligence. Due to the change in social roles, the elderly have nothing to do, and their potential preserved intelligence has not yet been fully utilized.
Therefore, through learning, training and motivation, the intellectual level of the elderly can be improved. In addition, the obvious decline in intelligence of some elderly people may be caused by other diseases such as cerebrovascular diseases, rather than problems with intelligence itself.