William Playfair Web writes:
It could be useful, if there are norms of reaction/ gene- environment interaction and/or dependence, but if additive heredity (Phenotype = Genotype + Environment), it’s largely not going to work unless heretibility is super high, which the evidence Robert has given has shown it’s not:
I have no problem with gentle Eugenics in theory, but in reality it may be fruitless.
Your group’s IQ would be barely above the previous mean in 2 generations – if one were to compensate for that, you’d have to continually make for only the upper portion of society that who want to breed, breed, consistently, so you’d end up diminishing your group’s population, severely.
The group regresses to the group mean is how I understand it. In other words, if you find a great big uninhabited island and put thousands of smart Blacks on there (average IQ = 120), what will happen is if you have two Black parents on that island with IQ’s of 145, their kids will tend to have IQ’s that crash back down towards that 120 mean, not the 85 mean for US Blacks as a whole. So the kids might have IQ’s of 132 instead of 145. That’s how it works. And yes, over time, you would end up with a bunch of really smart Black people on that island. I figure in 200-300 years, the Blacks on the island might still have 120 IQ’s.
Endless crashing back to the racial mean is irrational.
Look at the example above. What’s going on with US Blacks with average IQ’s of ~120? Well, what is going on with them probably is a higher frequency of whatever those smart genes are that increase IQ. Those same genes occur in the 85 IQ Black population, but unfortunately at a much lower frequency. They’re just not as common in that group.
After 200-300 years, no doubt those smart genes of those island Blacks would still be going on strong. Regression to the mean isn’t going to overrule those smart genes. And why would we expect this group to crash back down to 85 anyway? Look at their genetic profile. Look how different it is from the 85 IQ group. Why would they crash back down to 85 if they had such high frequency of those smart genes? It’s irrational.
The regression that will happen on the island though is that people with higher than 120 IQ’s will tend to have offspring that crash back down towards 120. My mother said regression to the mean has to happen “otherwise it would keep going up forever.” I don’t understand what she means by that, but apparently that is the logic behind regression to the mean.
For instance, you have some very tall people – 6’8 man and 6’4 woman. They have male kids. Well, their kids are going to crash back down towards the 5’11 mean for males in that society. They won’t go all the way to it. The boys might end up 6’2. I suppose my Mom makes sense though, in that very tall people have to crash back towards the mean because otherwise humans could keep getting taller and taller, and there are limits to human height due to the nature of our species. So now it is starting to make sense to me.