The differences in intelligence would also widen due to the extra environmental variation. To simplify things, if you take three groups, two raised in the same country and one raised on the moon and one of the groups in the country is identical to the one in outer space, the cognitive gap between the two groups in the same country will be more heritable, but that's also because the gap would be smaller. The environment diminishes heritability by increasing total variation.
Thanks for the helpful video, this really clarified things! I do have one question, though. You mentioned that as environment becomes more controlled, heritability increases, and as genetic variation increases, heritability increases, which makes sense. However, I wonder, which one takes precedence, genetic or environment variation? For example, take a pair of identical twins - same genetics, probably raised in a pretty similar (if not the same) environment. Then take a pair of distant cousins. Both vary a lot genetically, and both are probably raised in pretty different environments. Would the heritability for the twins or the cousins be higher? Does the controlled, similar environment of the twins make their heritability higher than the genetic differences of the cousins makes theirs?
Is this right? the heritability in identical twins must always be 0 (since they have identical genes) and so there is no genetic variation between them. This is confusing, because the word heritability at an intuitive level implies to me that if the heritability is high, then you would be more similar. Hmm
If I understood it correctly, heritability means the extent of the effect of genes on the fenotype relative to the environment. A high level of heritability means the genes have more impact on the fenotype than the environment does. And a low level of heritability means the environment has more impact than the genes.
@@SushiDud that’s why it only applies to populations because it would not make sense to compare someone from ex. Iceland and Morocco - the environmental differences would be so large that the variance among the individuals would almost certainly be attributed to the environmental differences. Simply, we would not be able tell genes and environment apart. This also confirms that heritability measures are never 100% accurate - even if it’s a population. The basic assumption is that populations share “same environment”, which we all know is not true. However, it is the best measurement we’ve got, I guess
I doubt I'll get an answer here from someone because the video is really old but I'll try anyway. I often hear this 80% heritability figure thrown around but if I understand the term correctly then this figure only makes sense in the context of a given population. If so, what population is this 80% figure referring to? The entire world? America? Europe?
@@paulcraig6976 No, because heritability is group-specific. You have to look at the study to get a sense of where it's applicable. I suppose if the heritability estimate comes from a study conducted on a certain community, say middle-class people in Sweden, and the sample size was large enough, you would be able to generalize that heritability estimate to explain IQ differences between people in that particular group. If the group is poorly defined, it's going to be increasingly less accurate though, and it can't say anything about heritability for another group or between groups.
idk why pseudoscience is pushed intelligence is a heritable trait i don know why people lie to themselves different races do have different rates of intelligence we are not all the same
Questioning the genetic component of IQ is "completely inappropriate"? Really? so much for science, then? I'm 1:43 into this video and I'm not watching the rest. You should be ashamed, Ryan.
I think maybe if I rewatch this is the morning I might understand 20% of the concept
I was very confused about heritability and this was very helpful to understand my course deeper!! thankyou :)
Very nice explanation! Worked for me where the textbooks failed.
Now let me show you my favorite example of *four twelve-year old boys locked in barrels* :)
The differences in intelligence would also widen due to the extra environmental variation. To simplify things, if you take three groups, two raised in the same country and one raised on the moon and one of the groups in the country is identical to the one in outer space, the cognitive gap between the two groups in the same country will be more heritable, but that's also because the gap would be smaller. The environment diminishes heritability by increasing total variation.
Learn about genetic expression and non coding genes
Excellent video, helps me with my MCAT.
This helped me a lot. Thank you so much!
Oh my thank you so much for the explanation! this really really helps me a lot!
thank you sooooooo much
Wow! this is great. Av a better understanding of my course work
Thanks for the helpful video, this really clarified things! I do have one question, though. You mentioned that as environment becomes more controlled, heritability increases, and as genetic variation increases, heritability increases, which makes sense. However, I wonder, which one takes precedence, genetic or environment variation? For example, take a pair of identical twins - same genetics, probably raised in a pretty similar (if not the same) environment. Then take a pair of distant cousins. Both vary a lot genetically, and both are probably raised in pretty different environments. Would the heritability for the twins or the cousins be higher? Does the controlled, similar environment of the twins make their heritability higher than the genetic differences of the cousins makes theirs?
You explain so so well wow!
Great sir... Thanks a lot to explain this concept with so much ease
thank you! :)
Very clear! thankyou
very helpful!
Thank you so much!
I gotta perform this experiment 😂
great explanation! thank you so much :)
Your picture is so beautiful
Is this right? the heritability in identical twins must always be 0 (since they have identical genes) and so there is no genetic variation between them. This is confusing, because the word heritability at an intuitive level implies to me that if the heritability is high, then you would be more similar. Hmm
If I understood it correctly, heritability means the extent of the effect of genes on the fenotype relative to the environment. A high level of heritability means the genes have more impact on the fenotype than the environment does. And a low level of heritability means the environment has more impact than the genes.
@@SushiDud correct
@@SushiDud that’s why it only applies to populations because it would not make sense to compare someone from ex. Iceland and Morocco - the environmental differences would be so large that the variance among the individuals would almost certainly be attributed to the environmental differences. Simply, we would not be able tell genes and environment apart.
This also confirms that heritability measures are never 100% accurate - even if it’s a population. The basic assumption is that populations share “same environment”, which we all know is not true.
However, it is the best measurement we’ve got, I guess
I doubt I'll get an answer here from someone because the video is really old but I'll try anyway. I often hear this 80% heritability figure thrown around but if I understand the term correctly then this figure only makes sense in the context of a given population. If so, what population is this 80% figure referring to? The entire world? America? Europe?
It means 80% of the variance in between individuals is 80% heritable.
@@paulcraig6976 No, because heritability is group-specific. You have to look at the study to get a sense of where it's applicable. I suppose if the heritability estimate comes from a study conducted on a certain community, say middle-class people in Sweden, and the sample size was large enough, you would be able to generalize that heritability estimate to explain IQ differences between people in that particular group. If the group is poorly defined, it's going to be increasingly less accurate though, and it can't say anything about heritability for another group or between groups.
So what would happen if the 4 quadruplets were raised in identical 4 barrels?
I don’t think the kids would know they’re in different barrels so the results might still be the same even if the barrels are the same
Maybe h=0.5 ?
@@rrussell21 was that just random or are you trying to say something? because I did not get it
You can’t measure heritability in that case because theoretically there would be no difference between their IQs
This helped a lot.
Explaination was on point.
Thank you so much. You people are doing a tremendous job, hope I could do the same in future.
anybody else think this dude sounds just like mike birbiglia?
idk why pseudoscience is pushed intelligence is a heritable trait i don know why people lie to themselves different races do have different rates of intelligence we are not all the same
Cope😢
Questioning the genetic component of IQ is "completely inappropriate"? Really? so much for science, then? I'm 1:43 into this video and I'm not watching the rest. You should be ashamed, Ryan.
I didn't get it
what are you talking about ??
Is this racist?