I've said this a lot, but I may not have explained it in detail before. I'm sceptical about the notion of intelligence. This isn't quite the same as believing there's no such thing as intelligence. It's more a question of whether it's useful.
At first, it might look as if intelligence varies a lot in the population. There are professors, brain surgeons and rocket scientists, and there are sewage workers, road sweepers and shelf-stackers. This is not to denigrate any of them, and in fact that is precisely my first point. Sewage workers are through the roof in the value of their work. Compared to them, almost anyone's job in an industrial society is practically worthless, except possibly for farm labourers. The utility of a sewage worker to society is stratospheric. They're practically in orbit. However, they're also not recognised, and if you were to have a job as a sewage worker, I can imagine you'd probably avoid mentioning it when you met people unless you were quite confident, and if an average person were to be given a wide selection of jobs and rate the likely intelligence of the person suited to the work, it would probably be one of the lowest.
Of course, just because a job is valuable it doesn't mean it takes intelligence to do it. Nonetheless, and this is my first peeve, doesn't it seem just a little bit suspicious that people are sorted into categories which mean the hottest and noisiest jobs, as the Simpsons once put it, are the ones which appear to need the least intelligence? And that the worst paid work is the work supposedly stupid people do?
Consider the ability to tolerate boredom during a manual task. That's a talent or possibly an acquired skill. It's also something which people of allegedly low intelligence are supposed to be very good at. If that's so, in what sense is it not a cognitive strength? I would suggest that it is and that the only reason it isn't considered one is that it seems like a weakness to the people involved in writing the textbooks and the like. It may also be that the people who write the textbooks think something completely different than what I'm saying they think here but that happens a lot, here and elsewhere.
Then there's the question of what you as a proper three-dimensional human being do with what you think. You might not want to appear too clever in front of people so as to avoid being stigmatised in some way, or you might not have the confidence to stand by the conclusions you have come to after a lot of thought when they are in fact valid. You might also be what I refer to as "intellectually lazy", although that too is unsatisfactory.
Calling someone stupid is ableist. Learning disabled people are not bad people, although presumably some are and some aren't like people who are not learning disabled. Due to this, I have been careful to call people intellectually lazy rather than stupid, as that's often what's meant. People, myself included sometimes, want the world to be simple and they want issues to be simple, so they will tend to bifurcate possibilities when in fact the true situation is frillier or twiddlier, as I mentioned before, or otherwise over-simplify. They could put the time and effort in but they don't.
It's recently been brought to my attention that describing someone as intellectually lazy is insulting. Sometimes it's intentionally so, but sometimes not, and this brings up two further issues. One is that someone may simply lack the confidence or the positivity in a particular situation to pursue an idea to its logical conclusion. The other is that free will may not exist! If that's so, the concept of insults themselves becomes dubious, as nobody can help what they do, but it still means that the process whereby people behave "stupidly" is not to do with how capable the isolated parts of their mental faculties which cogitate are. How meaningful or possible it is to isolate that bit is another matter.
Hence stupidity becomes a kind of vice, but in this view a vice is a little like a mental version of a disease which might be temporary or permanent.
Then we come down to organic differences. It does seem to make sense to say that just as some people are weaker than others, and some people have wasting diseases which make them abnormally weak, some people's ability to think things through is weaker than others', due to things like memory and attention, or the capacity to spot which patterns are valid and which aren't. On the whole, though, muscles can be trained and strengthened or they can become weaker through disuse, and although it's important not to extend a metaphor too far, my experience of how people's health is does strongly suggest that they are like this in many other ways too, so it makes sense to me that their minds and abilities to think would be generally responsive to intellectual stimulation, so they would be able to call on greater intellectual resources after some time or their minds might fall into disuse. Clearly, however, I do believe in the likes of dementia, so to that extent I believe in intelligence.
Finally, there's an issue illustrated by 'Futurama'. Philip J Fry is in a cell and has nowhere to go to the toilet, so he does it all over the floor "like an animal". Leela then points out that animals generally allocate one part of the floor to do that. Now, I can easily imagine someone "stupid" doing that and being trumped by a member of another species, perhaps quite a "lowly" one (that's problematic too). If we're going to try to arrange different species of animal into different levels of intelligence that way, it makes little sense that a language-using primate such as Fry is nonetheless unable to think of that option. Nonetheless it's easy to imagine that that might be so. It's even easy to imagine that a "stupid" version of a non-human animal would do that and an "intelligent" individual of the same species, say a cat, wouldn't. Also, other animals have intellectual capacities beyond ours, such as migration.
I haven't even mentioned multiple intelligences.
All of this, and probably some more stuff, is why I don't feel that the idea of intelligence is a very good or sensible one. Even if it does exist, it might be better to ignore it as it could be a self-fulfilling thing.
Oh wow, I just realised I've blogged on-topic by mistake for the second post in a row!