Intelligence tests are wildly over-rated. But tests of general mental ability can be very, very useful. For starters, they are the most consistent thing in terms of their ability to predict one’s performance on tasks out of any predictive test of performance. But the question is, what are we testing? And why is it so important?
The ‘g’ factor (and its babies)
In 1914, Charles Spearman came up with this idea, a thing he called ‘g’. He conceptualised a general commonality across all domains of mental performance. Some kind of single factor that influenced everything. This could be expressed numerically.
This kind of approach was contrasted with the approach of people like Joy Guilford who, in 1967 and after exhaustive analysis, came up with 180 separate elements or abilities that comprised our intelligence like operational abilities and semantic abilities.
These days, we’ve sort of come to the middle ground from these two opposing poles (something that happens quite often in psychology) and recognise that there is usually some kind of distinction between;
- crystallised intelligence (often referred to as ‘Gc’), which is our ability to apply existing knowledge to problems (like general knowledge or solving math equations); and
- fluid intelligence (often referred to as ‘Gf”), which is our adaptable problem solving ability (like figuring out what’s next in a sequence, or one of those infuriating situational ‘what’s the least amount of times you’d need to cross the river with these wildly incompatible animals so nothing dies’ questions).
But it’s not just what we’re measuring. It’s how we measure it. You might be familiar with the classic ‘Stanford-Binet‘ IQ test, which has to be delivered one-on-one. As a result it’s more costly and time consuming, but since it goes deep it can be more useful. Or it can be delivered in a group scenario (like Raven’s progressive matrices), which is less deep, but more easily applicable since you can do more people at once.
Why do we care?
But, surely cognitive ability isn’t as important as, say, practice? Well, that’s awfully naïve to think that one thing trumps another in all scenarios, hypothetical reader. But the fact is that people with higher mental ability and meta-cognitive (thinking about thinking; a higher order cognitive skill) skills;
- learn faster;
- apply existing knowledge better;
- apply principles to novel (completely new) problems more easily;
and like I said, it’s the most consistent measure if you want to be able to predict someone’s performance at tasks. Not to mention it’s a fairly cheap and cheerful way to go about testing it.
There are issues though. Testing for one’s general mental ability doesn’t let us measure specific abilities. But also, one of the things going for measuring this ‘g’ factor, or one’s overall general ability, is that meta-analyses (studies that review heaps of studies) really support them. But they may actually be over-emphasising its importance. See, ‘g’ might be related to all aspects of performance, but depending on what you’re actually getting someone to do it may not nearly be the most important. So when you average everything together, ‘g’ comes out on top, but it may not be nearly as good to look at when you’re looking at a specific thing.
But also, one of the things going for measuring this ‘g’ factor, or one’s overall general ability, is that meta-analyses (studies that review heaps of studies) really support them. But they may actually be over-emphasising its importance. See, ‘g’ might be related to all aspects of performance, but depending on what you’re actually getting someone to do it may not nearly be the most important. So when you average everything together, ‘g’ comes out on top, but it may not be nearly as good to look at when you’re looking at a specific thing.
Plus, it’s hard to always be fair when we’re testing for general mental ability. A lot of tests are culturally specific, especially when it comes to measuring things like crystallised intelligence (like general knowledge, right? I’m sure a lot of indigenous Australians from a rural background are less quick to differentiate between celebrities that your average, white-collar movie geek). These tests can reinforce socio-economic differences too; for example, timed tests might favour native speakers of a language and certainly will favour better educated ones.
So general mental ability is an extremely relevant part of who we are and how well we do. And although it’s not the most important thing, it’s one of the easiest and consistent things to measure which is why there’s such a focus on it these days. From schools, to jobs and even some social clubs everyone wants a good cognitive ability. Luckily, there’s one cheap and easy way to grow it; read a book!
The reason our smarts can’t be measure entirely by a cognitive test, is because there’s so much more to our mind than that. Read about the different kinds of psychology and learn what kind of armchair psychologist you’d make. Or read about the seven ways psychologists think about their relationships so you can hack your own. Giving you the dirt on your search for understanding, psychological freedom and ‘the good life’ at The Dirt Psychology.