Intelligence, rather than the not very useful IQ, definitely has a genetic link. However genes are themselves influenced by environmental factors, which can cause them to be activated or suppressed. When it comes to behavioural traits such as intelligence, prediction from genes is unclear. Brain development is sensitive to genetic influence, but it’s not completely determined by it. The way the brain gets “wired” depends on early experience in the womb, childhood and adolescence, and remains susceptible to environmental influences throughout life.

IQ is garbage. I'll put it to you simply. How can a single number sum up something as complex as human intelligence? What does intelligence even mean? How much you can remember? Process? Analyze? Synthesize? What about creativity and imagination? Don't they play a role in human intelligence? How does IQ measure them? IQ may measure some aspect of a larger system but may reflect more whether someone thinks a particular way (ie thinks more like the people who created the test questions). As to the genetic component to intelligence -- we don't really understand it well enough to make such a strong casual connection. It's so hard to tease out the effects of environment.

But memorizing answers is not the same as decoding words. There are many types of intelligences, but for some reason, we seem to value memorizing stuff more. I have a great memory & managed to skate by with C's in school without doing much work. I paid the price later, but I did manage to catch up.

Isn't the person who was asked to come up with some way of measuring intelligence meant to have said something along the lines of 'here it is, but don't use it' because he didn't think it was a good idea? It is very flawed - but an interesting thing to do anyway.