After decades of failed attempts to find the underlying thing that somehow could be partially-but-not-completely measured in this wide variety of ways, it dawned on people: there is simply no such thing as intelligence.

Or rather: what we intuitively respond to as intelligence is a composite, a symptom that can arise from a number of different factors in a number of different ways that are correlated but which function independently of one another.

It is true that people who think quickly can sometimes also learn more, and sometimes people who think quickly have more time to come up with creative results. But this sense of intelligence was an end result without a single cause; instead, it is what we see in the capabilities of a person who is able to harness any of a number of traits and get them to work together to produce a result.

In the end, a person can display intelligence by being very quick, or very knowledgeable, or very creative, or any mixture of these or other helpful traits.