In Part 1 of this series, we introduced some of the basic concepts and steps associated with the development of cognition and how more and more sophisticated responses to problems may have emerged in species.  In this part, we want to continue by exploring some of the elements that make up what we consider to be "intelligence".

Intelligence is defined according to Wikipedia as: “a property of the mind that encompasses … such as the capacities to reason, to plan, to solve problems, to think abstractly, to comprehend ideas, to use language, and to learn.” The definition goes on to include other elements such as creativity and personality, but also suggests that these aren’t necessarily accepted characteristics, so we’ll leave those out.

Whatever definition we use, we need to resist the temptation to view all forms of intelligence from a strict human perspective. There is no question that humans have developed a mental acuity that is unique, however it is also clear that in examining the anatomy of the brain, that its origins extend quite far into the past. To the best of my knowledge, there is no instance of an animal possessing a trait for which there are no evolutionary predecessors. Therefore whatever we consider human intelligence to represent, there must be earlier forms of it in other species.

We’ve already seen that many animals clearly have the ability to learn from past experiences, and to solve problems. It also seems reasonable to suggest that some animals are “reasoning” and thinking abstractly to achieve solutions to problems.

For example, when a horse let’s itself out of a stall, or a bird opens a cage, these are all examples of an animal that has clearly identified the particular element of the entire structure that warrants attention. In addition, they have understood that manipulating a handle or some other piece is necessary to achieve their objectives. Once they’ve figured out the “trick” of it, they are considerably faster the next time around which suggests that they have learned from the experience. However, one of the most important points we need to understand is that not all animals will respond the same way, nor will they solve the problem in the same manner, nor will they all attempt to solve it. It is impossible to distinguish lack of ability from lack of motivation in such circumstances.

Basically we know that animals can dream, learn, retain memories and use experience, display leadership skills including planning and management of others.

The idea of “comprehending ideas” as being an element of intelligence seems vague and not particularly useful. In general, I would argue that this is simply a variation of the “learning from experience” statement and doesn’t merit any special consideration. After all, an idea is nothing more than an abstraction of some experiential reference point. However, I will return to the concept of “ideas” a bit later in discussing human intelligence.

Similarly, the final point relating to language is similar to the previous elements in that many animals have what appears to be a language, but there can be little doubt that humans have extended that capability far beyond any other organism. I won’t consider the role of language directly although I would refer you to Patrick Lockerby’s excellent series on the Science of Human Language for a more comprehensive examination.

In short, the basic definition of intelligence that we started with seems to be present in a wide variety of animals, so the question that needs answering is; what is it about humans that makes their particular brand of intelligence unique? Most especially, it is worth considering whether it is something that is even measurable.

In the third part of this series we will consider how human intelligence varies from that which we have already looked at, and see whether it is a trait which is subject to direct measurement.