It is common to think that all human abilities decline with age past thirty , and that intelligence is no exception to this rule. However, it seems that this is not entirely true and does not always occur with all cognitive abilities equally.

We can believe this, among other things, because a team of researchers has found indications that certain aspects of intelligence reach their peak after youth, while others do so much earlier, around the age of 20.

The thousand faces of intelligence

Although we all tend to associate the concept ” intelligence ” with the set of skills that are put into practice when completing the famous IQ test , more and more layers of nuance are found in what might seem a rigid and monolithic definition. For example, there has been talk of emotional intelligence and multiple intelligences, concepts of intelligence that go far beyond what is measured through the classic sheets of paper on which the correct answer must be written. One of these interesting breaks in the idea of intellect has occurred with the proposal of two classes of cognitive abilities: those that give shape to fluid intelligence and crystallized intelligence.

These different ways of classifying types of intelligence are not free: are theoretical models that try to explain deep processes that occur in our brain and, therefore, our way of thinking. This is why it is interesting when evidence is found that different types of intelligence evolve differently. In this sense, an article published in the Journal of Applied Psychology points out that, while fluid intelligence (that is, that which is associated with the successful resolution of new problems) begins to decline in the third decade of life, crystallised intelligence, related to the management of what has already been learned, continues to improve with age until it reaches, in some cases, 70 years of age or more.

The experiment

A group of 3,375 volunteers between the ages of 20 and 74 with an executive-level professional profile were used for this research. As the research was focused on the evaluation of skills linked to the work environment, these people filled out a battery of questions related to certain professional skills, creativity and management style. In addition, they were given a test on fluid and crystallized intelligence and the skills associated with each of them.

n order to measure each of these modalities, the tests proposed exercises related to logical and analytical ability to measure fluid intelligence (such as following a series of letters), while crystallised intelligence was evaluated from tasks related to verbal ability .

After analyzing the collected data, the researchers found that older people showed significantly lower fluid intelligence scores than people under 30 , especially after age 50. However, in the verbal skill tasks associated with crystallised intelligence the trend was reversed: the average score corresponding to the older group was higher.

Although this is not the only study that describes these trends in the evolution of these types of intelligence, it is one of the few that focuses on the professional context. Research along these lines could be useful when it comes to knowing what type of tasks are easier to solve in one or another age group, with beneficial results for both the person and the work group in which he or she finds him/herself.

Of course, both types of intelligence decline with age , what happens is that they do it differently and from a different moment of maturity. It makes sense that this should be the case. Fluid intelligence is especially useful for adapting to relatively new environments to which one is not very well adapted and which can still cause unexpected events given the little experience of the individual. Crystallised intelligence, however, has a more conservative application, linked to solving problems from what is already known.

These two types of abilities unfold in different stages, and our brain seems to be able to adapt to these stages by adjusting to what is expected of it. Somehow, it seems as if evolution aspires to make us as wise as it is .

Bibliographic references:

  • Klein, R. M., Dilchert, S., Ones, D. S. and Dages, K. D. (2015). Cognitive Predictors and Age-Based Adverse Impact Among Business Executives. Journal of Applied Psychology, online publication. doi:10.1037/a0038991