6 ms·

Two people with IQ's of 120 will have kids with average IQ's of 110, but if you put those kids on an island and they have kids their average IQ's will be 110.

by baking 5y ago

Two people with IQ's of 120 will have kids with average IQ's of 110, but if you put those kids on an island and they have kids their average IQ's will be 110. What?

AbrahamParangi 5y ago
The original population has an avg IQ of 100 but the new island population has an avg IQ of 110
jasongi 5y ago
The parents genes are only 120 because 10 points were based on environmental "luck". Genetically they had the genes for 110 IQ +/- 10 points to accommodate the environmental luck. The two kids had average luck, so they got 110 IQ, but they still have the same genes. So when they have kids with others with the 110 IQ gene's, they will still be 110 +/- 10. A simpler explanation: you might be the child of geniuses but they dropped you on your head repeatedly as a baby. You might not be so smart as an adult because of it but your kids will have genius genes, not dropped on head genes.
- deleted 5y ago
  [deleted]
mattnewton 5y ago
In the first example, their IQ of 120 is from a mix of factors and the author estimates some percentage that is due to the environment outside genetics, and that is what is lost in reverting to the mean of the environment. In the second example the author assumes that the environment of the desert island contributes nothing to genetics and so the offspring get the full 110 (heritability is 100%). It's odd to me though because it wasn't clear that the environment was meant to be affecting the parent and not the child too- the trick is the author treats the heritability parameter different for the parent and the child. Also, I don't think the desert island would actually have no effect on the 110 generation's IQ, or their upbringing outside of it, but I guess I can accept it as a thought-experiment-only place that does that by definition and not a literal desert island.

6 ms·

Two people with IQ's of 120 will have kids with average IQ's of 110, but if you put those kids on an island and they have kids their average IQ's will be 110.

by baking 5y ago

Two people with IQ's of 120 will have kids with average IQ's of 110, but if you put those kids on an island and they have kids their average IQ's will be 110. What?

AbrahamParangi 5y ago
The original population has an avg IQ of 100 but the new island population has an avg IQ of 110
jasongi 5y ago
The parents genes are only 120 because 10 points were based on environmental "luck". Genetically they had the genes for 110 IQ +/- 10 points to accommodate the environmental luck. The two kids had average luck, so they got 110 IQ, but they still have the same genes. So when they have kids with others with the 110 IQ gene's, they will still be 110 +/- 10. A simpler explanation: you might be the child of geniuses but they dropped you on your head repeatedly as a baby. You might not be so smart as an adult because of it but your kids will have genius genes, not dropped on head genes.
- deleted 5y ago
  [deleted]
mattnewton 5y ago
In the first example, their IQ of 120 is from a mix of factors and the author estimates some percentage that is due to the environment outside genetics, and that is what is lost in reverting to the mean of the environment. In the second example the author assumes that the environment of the desert island contributes nothing to genetics and so the offspring get the full 110 (heritability is 100%). It's odd to me though because it wasn't clear that the environment was meant to be affecting the parent and not the child too- the trick is the author treats the heritability parameter different for the parent and the child. Also, I don't think the desert island would actually have no effect on the 110 generation's IQ, or their upbringing outside of it, but I guess I can accept it as a thought-experiment-only place that does that by definition and not a literal desert island.