Let’s start out by defining intelligence and an accurate way to measure it.
Yeah for all we know of is one of those guys who took an IQ test online and now has it in all of his social media bios.
Go ask a chimpanzee 😆
Okay, so forgive the glib answer, but yeah, obviously on the macro level our genetic differences with the other apes contribute massively to our difference in intelligence with them.
At the micro level - i.e. between individual humans - my understanding is that the evidence also suggests that genetic variations lead to variation in intelligence (of course, as mentioned by other commenters, the usual caveats of how exactly you define and measure intelligence apply.)
Researchers found that the IQ of children adopted at birth bore little correlation with that of their adoptive parents, but strongly correlated with that of their biological parents. What’s more, this association became stronger as the children grew older.
In fact, hundreds of studies all point in the same direction. “About 50 per cent of the difference in intelligence between people is due to genetics,” he says.
Although each gene associated with intelligence has only a minuscule effect in isolation, the combined effect of the 500-odd genes identified so far is quite substantial. “We are still a long way from accounting for all the heritability,” says Plomin, “but just in the last year we have gone from being able to account for about 1 per cent of the variance to maybe 10 per cent.”
Also: https://www.une.edu.au/connect/news/2022/10/multiple-insights-in-a-decade-of-twins-data
The longitudinal Academic Development Study of Australian Twins (ADSAT) is the first project of its kind in Australia and has amassed revealing data on 2,762 twin pairs, 40 triplet sets and 1,485 non-twin siblings. Using the National Assessment Program: Literacy and Numeracy (NAPLAN), and regular parent surveys, it has given researchers a unique picture of the behaviours and demography that contribute to educational achievement – and the extent to which our genes influence them.
Genetic differences among students are the single biggest influence on differences in literacy and numeracy standing and growth, accounting for half or more of that variability across tests and across time.
Yes general intelligence is related to genes. Two important caveats:
-
Don’t forget the environment. See the Flynn effect, according to which measures of general intelligence have risen over time, showing the effect of the environment. This is just like height. The Dutch were once amongst the shortest people in Europe, and now they’re amongst the tallest. It’s true that they are tall now, in part, because of their genes, but, since they used to be short, obviously there’s much more to height than just genes. The best genes won’t help an unwatered seed sprout. Someone with low intelligence now might have the genes of a genius, if only they had received an education.
-
Racists are still wrong. There is an overwhelming consensus that there is no genetic basis for race. There is no gene or set of genes or distribution of genes that all and only members of a race have. In fact, there is more genetic variation within races than between races!
-
Intelligence has a genetic component. Every single test we have that attempts to measure intelligence that we’ve checked for heritability shows that intelligence likely has a generic component. Furthermore, we know that some species are more intelligent than others. Given the demonstrable existence of Darwinian evolution, this implies that some populations of a species are more or less intelligent than another because that’s a requirement for a speciation event that results in a species that’s more intelligent than its cousin species.
Anyone who says otherwise is likely allowing their ideology to cloud their judgement.
Conversely be on guard against people that say this proves any particular population, especially based on specific phenotypes, is inherently more or less intelligent than any other. They most likely also have an ideological axe to grind.
That besides the fact that, as another commenter mentioned “intelligence” is a pretty nebulous term to begin with.
This exactly. Intelligence being heritable does not imply that any one particular population is more intelligent on average than another.
“intelligence” is a pretty nebulous term to begin with
This is also accurate, but I’m glossing over that because it’s late and that fact is only tangentially relevant to the question.
Does that apply to intelligence as a whole or does it vary for different skills (i.e. logical reasoning like math vs more creative skills like reading/writing.
I’m intoxicated so fuck me.
Yes. There is a genetic link to IQ.
IQ doesn’t test all kinds of intelligence though.
Iirc, you can alter your IQ, just as you can expand your other intelligence areas acumen.
In developing a specific intelligence acument (verbal, logic, interpersonal, nature, et al), you increase the odds that your offspring develop similar acumen
Iirc this finding is significantly leaning towards nurture, and not nature (,genetic)
Anyways cheers goodnight someone smarter than me please correct and source if you’re diligent and stuff
My personal take is that intelligence is much like muscular strength. Genetics probably play a role but the more important factor is how you use and train your cognitive strength. A cognitively sedentary person will almost always be less intelligent than a cognitively active person, I doubt genetics play a large role unless we’re talking about people who put similar levels of effort into their development and upkeep.
Yes. We have plenty of studies indicating that IQ deviation (for lack of a better measurement) is heritable.
This is even observable casually - plenty of people gossip about $LOCAL_FAMILY having a history of Darwin award attempts, or how $OTHER_FAMILY is stuffed with straight-A engineering students.
However, it’s only a component, not the whole story. Intelligence can be built up like muscle - Joe Average who trains will beat out Sally Smartypants who doesn’t.
It’s also going to be very dependant on upbringing which usually would go hand in hand, if someone grows up rich going to all the best schools and getting all the opportunities, not having to work when young etc they’re probably going to end up more academically intelligent than someone who grew up in a family just barely getting by
No I don’t think so. Its definitely more of an enviromental upbringinf and personality predisposition thing. Some people just simply aren’t heavy thinkers or curious about anything. They live their life one day at a time in the moment without really contemplating anything. Its not genetic inheritances, its just how they choose to be/are.
Genetics is a scientific concept.
Intelligence is an unscientific concept.