In this video I describe the Flynn Effect, which refers to the dramatic rise in average IQ over the past several decades. Environmental factors like improved nutrition and access to education may partially explain this improvement and people who were previously held back may now be better able to reach their fullest IQ potential. This doesn’t fully explain the effect and there are limits to these types of improvements that we may now be reaching, perhaps explaining why the increase may be slowing.
James Flynn on the Flynn Effect: https://www.youtube.com/watch?v=9vpqi…
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Video Transcript
Hi, I’m Michael Corayer and this is Psych Exam Review. In this video we’re going to talk about the Flynn Effect and consider some environmental factors that might be related to IQ scores. So in the past two videos we looked at performance gaps between the sexes and between races. So we looked at possible differences in task performance and then we looked at differences in average group performance in terms of IQ score. And we’ve considered that there could be some biological explanations for these gaps.
Now it could also be the case that there are environmental explanations or interaction of biological and environmental explanations for explaining these gaps. So for instance we could look at something like the fact that Asian students routinely outscore their white American counterparts in math performance. We might consider that this could be genetic, maybe there’s some genetic difference between the races that’s accounting for this performance gap? But when we consider that Asian students spend an estimated 30% more class and homework time on math, then we might think that maybe environment is playing a role. Maybe there’s different cultural pressures on students and different expectations in terms of their math performance and this is at least partially explaining this difference in performance.
So another way we can think about differences in performance is to think about differences over time. Rather than comparing people now, comparing let’s say different races in terms of their average performance today, we could think about overall populations compared to populations in the past. So this brings us to what’s called the Flynn Effect. This is a term that was coined by Richard Herrnstein and Charles Murray in The Bell Curve and it refers to research by James Flynn on the rise in IQ over time. So Flynn demonstrated that the average IQ seems to have risen about 3 points per decade over the past few decades. Now the average IQ score is still going to be 100, the average IQ score today is 100, but the tests are constantly rescaled and so what this means is that the tests have gotten a little bit harder and that your performance is only compared to people today. And so that means the average score will still be 100.
So for instance if you had a group of people who scored 100 on a test today, if they were to take a test from 30 or 40 years ago, they’d probably score about 110. Now if we extrapolate from this, we start to wonder, you know, just a few generations ago, was everybody a moron? You know, with the average IQ 70 or below? That doesn’t seem to make much sense. I mean if we went back a few hundred years it would mean that, you know, everybody was suffering from intellectual disability. And that’s probably not likely to be the case. So what’s going on here and how is this happening?
Well, one thing we can consider is that well maybe there’s, you know, natural selection occurring. There’s some sort of advantage for higher IQ and it’s being selected for and that’s causing us to have this increase in IQ over time. That would be a sort of genetic explanation. But when we look at this we realize, well that doesn’t make any sense because it’s happening far too quickly for selection to be occurring. You know, evolution occurs over much much longer periods of time. It doesn’t happen in a decade. So we can probably rule out that our genes are changing this quickly.
So if we rule out genetic factors then we’re left with some environmental factors. So now we’ll consider what these environmental factors might be that could explain this dramatic rise in IQ. The first of these is nutrition. So we can consider that as nutrition improves in certain areas, we also see that the average IQ score tends to go up. Now this is not about an individual basis, right? We’re talking about the overall population. I’m not saying that if you, you know, eat a salad and take some vitamins that your IQ is going to go up. But what I’m saying is that if fewer people are malnourished then you’re going to have fewer scores that are being sort of pulled down, right? So when we have fewer children who are malnourished then we’re not going to have as many of those lower scores. So if children are malnourished, they don’t have adequate nutrition, then that’s going to hinder their development and they’re probably not going to reach their fullest genetic potential for IQ.
So we imagine everybody has some genetic potential for IQ but if you don’t get adequate nutrition then you aren’t going to reach that. So you’re going to end up sort of on the left side of the curve there with a lower IQ score. But if we improve nutrition for those children as they’re developing then their scores are going to be pushed up and that’s going to push up the average score as well. Now we can also think about this not just in terms of overall nutrition but in terms of what we might think of as small differences; things like the introduction of iodine into table salt. You might think that wouldn’t seem to matter much but introducing iodine into table salt has been estimated to be responsible for several points of average IQ increase. And the reason for that is that it prevents iodine deficiency disorder and iodine deficiency disorder causes cognitive impairments and can lead to intellectual disability. So by preventing this iodine deficiency disorder, you know, all these people who in the past, they didn’t have iodine in their diet they developed IDD and their IQ score was sort of stunted. And now that’s not happening anymore. They’re going to reach their potential and that’s going to mean they’re gonna have higher IQ scores and that’s gonna also help to push the average up.
Alright, and we could even see this with other things that I’ve talked about like PKU. So in the past if you had PKU, this phenylketonuria, and you were exposed to phenylalanine then you’d have cognitive impairment and you know that was that. We didn’t know about it. Now that we can identify PKU at, you know, a very, very early point and we can ensure that you’re not exposed to phenylalanine through a very strict diet, well then now you’re not going to have that cognitive impairment. And so your IQ score is probably going to be higher. Alright, so that’s some ways that nutrition can be involved in this rise in IQ score but it doesn’t fully explain it.
So we can also consider education has a broad environmental factor related to IQ and so one thing that we might notice is that people spend a lot more time in school then they used to in the past. So if we look even just a few decades ago or you know we look a hundred years ago we think about the average person, the amount of time that they’re spending in school is much much higher. So if we look at the percentage of the population that graduated from high school even you know 50 or 60 years ago, it’s much lower than it is today. And then we consider how many people go to college and complete college and then earn even higher degrees, you know? People are spending a lot more time in school, so this could be related to rise in IQ score. And it’s not just that people spend more time in school, it’s that the type of education has also changed.
So Flynn has argued that we do a lot more abstract reasoning now than we did even just 30 or 40 years ago. So the type of education has changed. There’s a much greater focus on abstract reasoning and that’s particularly important because that’s a big part of what IQ tests are about. They involve abstract reasoning, hypothetical situations, working with new problems that you haven’t worked with before. And we have much better training in terms of how often we’re doing that, how many years we’re doing that in school. We’re doing it day after day. We’re always dealing with these abstract reasoning problems in school to the extent that we didn’t have in the past. You know, your grandparents weren’t doing as much abstract reasoning when they were kids in school as kids are doing at school now. And so this might also explain this rise in average IQ.
Now another thing is that this effect seems to be slowing and perhaps it’s coming to an end. Maybe IQ won’t continue to rise so much in coming decades. So if the effect has been slowing this actually suggests that we’re sort of reaching the limits of improvements in nutrition and improvements in educational opportunities for students. So in the past, you know, things were pretty bad for a lot of people in terms of their access to nutrition or their access to education and we’re changing that very, very dramatically. That’s, you know, we’re lifting people out of poverty, you know, at a rate that is unprecedented. And so we’re doing all that we can to improve this but maybe there’s going to be a limit and maybe we’re already approaching it in terms of people who were previously holding down the average because of lack of nutrition, lack of education. Now those people are no longer holding it down. They’re reaching their fullest potential so that’s pushing the average up and maybe we’re going to have a more level playing field for everybody.
But it’s probably not the case that IQ is going to continue rising at this rate forever, right? So maybe we’re reaching the limits of how much we can improve the average in terms of having more people have access to nutrition and having people have better access to education. And so that would suggest that if we’re reaching the limits of these, that these probably are the explanation for this rise at least in the past few decades.
But these aren’t the only explanations for possible differences in IQ performance over time or between groups today. So that’s something that we’ll start looking at in the next video; we’ll consider some more detailed environmental factors that could be playing a role. I hope you found this helpful, if so, please like the video and subscribe to the channel for more. Thanks for watching!
