A very common belief here is that most human behaviour is based on Paleolithic genes, and only trivial variations are cultural (memetic), coming from fresh genes, or from some other sources.
But how strong is the evidence of Paleogenes vs memes vs fresh genes (vs everything else)?
Fresh genes are easy to test—different populations would have different levels of such genes, so we could test for that.
An obvious problem with Paleogenes is that there aren’t really that many genes to work with. Also, do we know of any genetic variations that alter these behaviours? If preference for large breasts was genetic, surely there might be a family somewhere with some mutation which would prefer small breasts. Do we have any evidence of that?
So I suspect memes might be much more important relative to Paleogenes than we tend to assume.
I think we can fairly easily come up with examples of things that are regarded as attractive in some cultures and not others.
For example, tanned skin. Back in the “olden days” in Europe, pale skin was considered the ideal. The much-desired “fair maiden” in old tales is literally one with light-colored skin that is kept out of the sun so it doesn’t tan. Today, in the U.S. at least, skin with a slightly bronze tan is often considered the ideal.
This may or may not have to do with social class. Prior to industrialization, lower class people would be tanned from working outside on farms, while higher class people (nobility, etc.) could stay inside and keep their skin nice and pale. Once poor people switched from working on farms to working in indoor factories, they, too, had pale skin, while the wealthier could afford to waste time sitting in the sun getting a tan. “Find signals of high status attractive” might be a genetically influenced trait (I’d be surprised if it weren’t) but genes don’t seem to determine exactly how people signal high status.
Plenty of behavior has genetic influences, but people learn an awful lot from their environment, too. When a dog is trained to roll over on command, is that a genetic behavior? If it is, then so is everything and it becomes a meaningless category.
If preference for large breasts was genetic, surely there might be a family somewhere with some mutation which would prefer small breasts. Do we have any evidence of that?
Brain-coding phenomena like sexual preferences seem to be built from large collections of genes that are interconnencted with other systems, such that there aren’t many possible mutations that would undo the feature without wreaking havoc elsewhere in the phenotype as well.
In fact, the universality of such preferences across neurologically intact humans is evidence that they come from Paleogenes rather than memes or fresh genes, either of which can more easily be altered without deleterious effects elsewhere.
I’m not saying Paleogenes are not a possible explanation, but I haven’t seen much in terms of such evidence like:
I don’t think it’s so common for people to go around the world, and actually verify that people in statistically significant number of virtually isolated tribes do have preferences for larger breasts etc. So universality is more postulated than actually empirically found. Even if you find extremely common behaviour, it can still be memetic, as a lot of memes are copied from parents to children. How many behaviours are empirically known to be universal?
Mutations to such genes would be non-lethal, and some would only mildly reduce inclusive fitness. We have plenty of genetic diseases in the population affecting more important genes. So how come we haven’t discovered mutations in the wild that alter genes controlling this supposedly genetic behaviour.
We know very few genes obviously linked with behaviour, and saying it’s coded by emergent interaction of multiple genes is just handwaving away the problem. There’s a pretty low ceiling of how much can be straightforwardly coded this way, and I’d expect some serious evidence of some mechanism of complex genetically coded behaviour.
The 10000 year Explosion shows very good evidence that this isn’t quite true; many significant genetic adaptations are indeed far more recent and have been developping faster since the end of the Paleolithic.
A very common belief here is that most human behaviour is based on Paleolithic genes, and only trivial variations are cultural (memetic), coming from fresh genes, or from some other sources.
...
If preference for large breasts was genetic, surely there might be a family somewhere with some mutation which would prefer small breasts. Do we have any evidence of that?
Maybe there is also disagreement about what is and isn’t a trivial variation.
If preference for large breasts was genetic, surely there might be a family somewhere with some mutation which would prefer small breasts. Do we have any evidence of that?
On the other hand, do we have disconfirming evidence? (Would we expect to have noticed?)
All such evidence would be expected to come from different times or from isolated communities, today vast majority of the world population lives in one connected memetic soup. Unfortunately I don’t know enough about anthropology to give particularly convincing evidence.
Wikipedia search suggests some cultures don’t care much about breasts at all, what you can consider weak evidence against Paleogenetic explanation.
Wikipedia search suggests some cultures don’t care much about breasts at all, what you can consider weak evidence against Paleogenetic explanation.
Weak, yeah. After all, Westerners consider the face to be a great part of a person’s sex appeal, and it’s very important in sex (kissing, oral sex, etc.) - yet they don’t cover it up. Do they not care?
What’s really needed is data showing that breast size or proportions are uncorrelated with reproductive success, or at least with ratings of attractiveness.
“All conventional theories of cultural evolution, of the origin of
humans, and what makes us so different from other species. All other
theories explaining the big brain, and language and tool use and all
these things that make us unique, are based upon genes. Language must
have been useful for the genes. Tool use must have enhanced our
survival, mating and so on. It always comes back, as Richard Dawkins
complained all that long time ago, it always comes back to genes.
The point of memetics is to say, “Oh no it doesn’t.” There are two
replicators now on this planet. From the moment that our ancestors,
perhaps two and a half million years ago or so, began imitating, there
was a new copying process. Copying with variation and selection. A new
replicator was let loose” [...] - Sue Blackmore.
There’s very convincing evidence that ability to use language is genetic, up to specific kinds of brain damage and specific kinds of genetic diseases that cause very particular types of language impairment. Language itself is memetically built on top of that.
I’ve never seen such evidence for any other kind of behaviour.
I am not sure what you mean—or how it is relevant. Plenty of behaviour has a genetic basis. Eating behaviour and sexual behaviour, for instance. If you look at all the reflexes and instincts out there, you will see that many types of behaviour have a genetic basis.
Even if everything was learned (the “blank slate” hypothesis) - so what? How would that be relevant to the idea of cultural inheritance being significant?
A very common belief here is that most human behaviour is based on Paleolithic genes, and only trivial variations are cultural (memetic), coming from fresh genes, or from some other sources.
But how strong is the evidence of Paleogenes vs memes vs fresh genes (vs everything else)?
Fresh genes are easy to test—different populations would have different levels of such genes, so we could test for that.
An obvious problem with Paleogenes is that there aren’t really that many genes to work with. Also, do we know of any genetic variations that alter these behaviours? If preference for large breasts was genetic, surely there might be a family somewhere with some mutation which would prefer small breasts. Do we have any evidence of that?
So I suspect memes might be much more important relative to Paleogenes than we tend to assume.
I think we can fairly easily come up with examples of things that are regarded as attractive in some cultures and not others.
For example, tanned skin. Back in the “olden days” in Europe, pale skin was considered the ideal. The much-desired “fair maiden” in old tales is literally one with light-colored skin that is kept out of the sun so it doesn’t tan. Today, in the U.S. at least, skin with a slightly bronze tan is often considered the ideal.
This may or may not have to do with social class. Prior to industrialization, lower class people would be tanned from working outside on farms, while higher class people (nobility, etc.) could stay inside and keep their skin nice and pale. Once poor people switched from working on farms to working in indoor factories, they, too, had pale skin, while the wealthier could afford to waste time sitting in the sun getting a tan. “Find signals of high status attractive” might be a genetically influenced trait (I’d be surprised if it weren’t) but genes don’t seem to determine exactly how people signal high status.
Plenty of behavior has genetic influences, but people learn an awful lot from their environment, too. When a dog is trained to roll over on command, is that a genetic behavior? If it is, then so is everything and it becomes a meaningless category.
Brain-coding phenomena like sexual preferences seem to be built from large collections of genes that are interconnencted with other systems, such that there aren’t many possible mutations that would undo the feature without wreaking havoc elsewhere in the phenotype as well.
In fact, the universality of such preferences across neurologically intact humans is evidence that they come from Paleogenes rather than memes or fresh genes, either of which can more easily be altered without deleterious effects elsewhere.
I’m not saying Paleogenes are not a possible explanation, but I haven’t seen much in terms of such evidence like:
I don’t think it’s so common for people to go around the world, and actually verify that people in statistically significant number of virtually isolated tribes do have preferences for larger breasts etc. So universality is more postulated than actually empirically found. Even if you find extremely common behaviour, it can still be memetic, as a lot of memes are copied from parents to children. How many behaviours are empirically known to be universal?
Mutations to such genes would be non-lethal, and some would only mildly reduce inclusive fitness. We have plenty of genetic diseases in the population affecting more important genes. So how come we haven’t discovered mutations in the wild that alter genes controlling this supposedly genetic behaviour.
We know very few genes obviously linked with behaviour, and saying it’s coded by emergent interaction of multiple genes is just handwaving away the problem. There’s a pretty low ceiling of how much can be straightforwardly coded this way, and I’d expect some serious evidence of some mechanism of complex genetically coded behaviour.
http://the10000yearexplosion.com/
The 10000 year Explosion shows very good evidence that this isn’t quite true; many significant genetic adaptations are indeed far more recent and have been developping faster since the end of the Paleolithic.
It’s also an enjoyable read.
Maybe there is also disagreement about what is and isn’t a trivial variation.
On the other hand, do we have disconfirming evidence? (Would we expect to have noticed?)
All such evidence would be expected to come from different times or from isolated communities, today vast majority of the world population lives in one connected memetic soup. Unfortunately I don’t know enough about anthropology to give particularly convincing evidence.
Wikipedia search suggests some cultures don’t care much about breasts at all, what you can consider weak evidence against Paleogenetic explanation.
Weak, yeah. After all, Westerners consider the face to be a great part of a person’s sex appeal, and it’s very important in sex (kissing, oral sex, etc.) - yet they don’t cover it up. Do they not care?
What’s really needed is data showing that breast size or proportions are uncorrelated with reproductive success, or at least with ratings of attractiveness.
Sure:
“All conventional theories of cultural evolution, of the origin of humans, and what makes us so different from other species. All other theories explaining the big brain, and language and tool use and all these things that make us unique, are based upon genes. Language must have been useful for the genes. Tool use must have enhanced our survival, mating and so on. It always comes back, as Richard Dawkins complained all that long time ago, it always comes back to genes.
The point of memetics is to say, “Oh no it doesn’t.” There are two replicators now on this planet. From the moment that our ancestors, perhaps two and a half million years ago or so, began imitating, there was a new copying process. Copying with variation and selection. A new replicator was let loose” [...] - Sue Blackmore.
There’s very convincing evidence that ability to use language is genetic, up to specific kinds of brain damage and specific kinds of genetic diseases that cause very particular types of language impairment. Language itself is memetically built on top of that.
I’ve never seen such evidence for any other kind of behaviour.
I am not sure what you mean—or how it is relevant. Plenty of behaviour has a genetic basis. Eating behaviour and sexual behaviour, for instance. If you look at all the reflexes and instincts out there, you will see that many types of behaviour have a genetic basis.
Even if everything was learned (the “blank slate” hypothesis) - so what? How would that be relevant to the idea of cultural inheritance being significant?
I agree with this.