When exploring the relationship between age and intelligence it is important to understand that we are comparing two very amorphous concepts. When we talk about age we can be talking about biological age, mental age, epoch, historical milieau, or the passage of time. When we talk about intelligence we can be talking about adaptive behavior, genetic proclivity for problem solving, access to knowledge, or some factor “g” that Psychologists like to talk about. I prefer to think of these in terms of the measureable and observable, so I choose to talk about Mental age and Biological Age, also known as Chronological Age, in terms of problem solving ability.
If we take the developmental approach we can talk about age as Biological Development, and Intelligence as Mental age, as concepts meaning the age at which certain problems and perspectives are expected to be present in the individual. The common relationship here is that we expect human beings by certain developmental milestones to be able to accomplish specific adaptive tasks that lead to their ability to survive and thrive in a population. If a young person age 5 is solving problems that a 5 year old is expected to be able to solve we call him average, i.e., he has the average ability to solve what is expected. If a five year old is solving problems at the 2.5 year old level, we call him significantly below average, and if the five year old is solving problems at the 7.5 year level, we call him significantly above average. Corresponding Intellgence Quotients for these two scenarios would be 50 for the former, and 150 for the latter in a formula Mental Age over Chronological age times 100, which is the standard formula for figuring intelligence. The individual who is average would be given an IQ of 100.
Some would say then that the individual who has a 150 IQ is inherently more intelligent than the person with the 50 IQ and the 100 IQ, but is that true? In the younger years it is known that infants are constantly learning and by the age of one have learned significant communication, locomotion, and relating skills. They know when they want food, they know who their caretakers are, and they can interpret and communicate internal states such as “Tired,” “Hungry,” “Hot,” “Cold,” and so on. At age one the level of function of the person with a 100 IQ and the level of function of the person with 150 IQ are essentially undistinguishable, while the person with the IQ of 50 may not yet be able to accomplish any of these skills. To the observer, then, the child with the lowest IQ is noticeable as being different, while the other two are not differentiated by the observer. In this sense, the 150 IQ is no more beneficial than the 100 IQ.
As life progresses, however, the problems of living do not decrease, but increase. This is where the advantage of high intellience is the most productive for the person, because we would expect a person to benefit faster and to a higher degree from the learning proceess if they are more intelligent , and be more capable again than the person with the 100 IQ. But does this bear out in practical application? At the age of adulthood there are specific skills that all adults are expected to have, and the concept of “g” again says that the average person with the average IQ performs average in these skills. But at the 150 level, is this person perhaps more able and more capable of performing the average problem solving? Is this person going to cook smarter, drive smarter, sleep smarter, and hence be seen as more capable? Perhaps so, but in the real world the actual IQ is meaningless at this level , as a person who has all the required and necessary capabilities for survival is perceived exactly the same way as their peers.
We oftimes confuse Intelligence with achievement, and it is an easy trap in which to be ensnared. In this case, the person with a 50 IQ may never be able to achieve that which is to be expected, but the persons with average and above average IQ’s are expected to achieve the required adult skills. If the world provides for more complex problems, and more complex problem solving, the higher intelligence (150) person may, if exposed to such a problem, solve the problem faster and at a higher level of functioning, but such a scenario does not exclude the case where the individual with the 100 IQ has been previously exposed to a given problem, coming to the solution faster and easier using patterns from experience. This is where the concept of age in the realm of experience becomes a more important factor. A person age 20 with 150 IQ given problem “X” for the first time will hardly ever match a person with an IQ of 100 and even one year more of experience with the same problem “X”, in coming to a solution. In this sense the IQ is not a significant advantage at that point in time. But as the person with 150 IQ approaches the level of experience of the person with the 100 IQ one might expect that problem solving of problem “X” will be faster and easier for the individual. The outcome in the end may not be significantly different, but the ease and speed of the problem solving may be.
This is why we call experienced intelligent people “wise.” Their level of problem solving and experience in problem solving is the factor associated with their age, and their ability to match conditions or patterns of problems with their experience results in specific processing ability afforded by the 150 IQ that is greater than the person with 100 IQ. In this case, speed and ease are definitely factors that can be significanlty observed as differing among the aged and experienced. Both may wear the robes of the aged and wise, but the higher IQ person most likely gets the solution faster and easier. This condition has held true in our studies of older people as their motor processing skills may decline but linguistic and pattern matching skills continue to develop, barring senescence. And there is even some evidence that individuals who are senescent may be able to match patterns in problem solving even though their processing new information is impaired.
In this essay it was chosen to use the concepts of Mental Age and Biological, also known as Chronological age, as the defining concepts to relate Intelligence to Age. The relative IQ factors were discussed with comparison in the expected levels of problem solving along the lifespan. Less significant differences between the Average and Above Average IQ were posited and an example portrayed. A conclusion of IQ being significant only when combined with experience and in the areas of ease and speed of problem solving were postulated.
