Genes are the reason for this and that

[rkos]

There's constantly people saying that genes are the reason for this and that. But I don't get it, as far as I know we have somewhat of an understanding of what genes do. And if I'm not completely mistaken what genes do is encode a certain family of proteins and regulate their expression in the cells.
Now exactly how does a certain protein being expressed at a certain time affect human behaviour and culture? Doesn't the brain mostly shape itself from stimuli from the environment?
Is there any example of a clear link between a protein and behaviour?
Certainly the proteins make the structure of the body, but how does the structure of your body make for your culture? Isn't culture, technology, language, all that just an accumulation of memory stored in the brain and other external devices? And that memory doesn't come from a gene.
Is behaviour really not learned? Or if it's partially affected by genes, how?

I ask because I recently met some race and intelligence people(about intelligence, are we really sure it is some intrinsic quality and not just a label we give to people we like and who happen to behave in some way recognizable as "intelligent"(and this goes back to the question of how does a protein make behaviour) eg. paying attention to some important detail that most overlook, reasons for which could be many?) who insist on genetic differences being a leading cause of cultural differences and this got me thinking that it is really a much more widespread notion that "we are our genes" or whatever. And I did not know of any other place to ask.

So the bottom line is, are genes really so important and can anyone provide an example of how a gene modulates human behaviour?

 

[Monique]

Genetic differences are definitely not a leading cause of cultural differences. Genes do modulate human behavior, but it is a very difficult subject to study since there are so many environmental factors that are difficult to control. The clearest examples will come for animal studies, where some mutations will make mice extraordinarily inquisitive and other mutations make them prone to giving up in adverse situations. We however are behaviorally much more complex than a lab mouse.

 

[Deoxyribose]

Now exactly how does a certain protein being expressed at a certain time affect human behaviour and culture?

As Monique said, human behavior and culture is probably just as related to the environment as it is to genes. There is no gene that will make you a Ladies' man, but the level of expression of a certain gene may be related to the number of times you attempt to interact with conspecifics before giving up. If it is true that human behavior is a function of roughly 20,000 genes interacting with its environment, then deciphering which genes contribute to which behaviors would be a tricky task.

Keep in mind that no one knew that genes were proteins and that DNA was the genetic material when genes were first thought of. It was simply known that offspring tended to resemble their parents.

Doesn't the brain mostly shape itself from stimuli from the environment?
Is there any example of a clear link between a protein and behaviour?

It does, but genetics is intricately linked to how neurons respond to environmental signals. Though the cellular basis of learning and memory is still being investigated, it appears to involve changes in gene expression induced by signaling from adjacent neurons.

What changes about your brain when it learns something new? When you meet a new worker at the office, what about your brain is different that allows you to remember that worker's name? Is it the number of neurons, or is it the way those neurons are connected? Either way, it's going to involve changing protein levels in order to change the connections between neurons or to make new neurons from glial cells. Different genetic sequences may be related to how often you have to read a paragraph before absorbing the information, or how many times you have to repeat a phrase before memorizing it.

To address the question of whether or not genes cause cultural differences: look at identical twins and compare and contrast their morphology and behavior. They look similar, but different environmental exposure shapes them into two different personalities. However, teasing apart how much of their behavior is genetic and how much is environmental is no small feat.

But genes are incredibly important; more important than I understand. Our generation has shown that if we can figure out the optimal genetic sequence to survive in certain conditions, then we have the capability to synthesize that genome. I'll bet that genetic testing will become more and more important to insurance companies in the next few decades. And a firm understanding of genetics is necessary to prevent rich & powerful people from misunderstanding the role genes in behavior and attempt to conduct a genetic cleansing.

 

[arildno]

However, DO remember that we are specifically geared, by our genes, to be susceptible to environmental input.

The correct default option is NOT that anything goes, but that genes controls everything.

Specific gene combinations are needed to make the organism environmentally sensitive.

Some organisms might be said to be less environmentally sensitive than others; in an evolutionary context, that type of behaviour can only become dominant in largely uniform environment, for other organisms, environmental sensitivity is a strongly adaptive factor, and a sub-population that sensitive will outcompete their less flexible brethren/sisters.

 

[Mkorr]

When a scientist uses the slightly sloppy metaphor "a gene 'for' X", he means something like "the existence of a genetic influence that would make it statistically more likely for an organism to exhibit phenotypic characteristic X, if all other factors remain constant". It is not trying to argue for genetic determinism (that idea that environmental influences have no effect) and it is not trying to assert that there is always a 1:1 correspondence between a gene and a phenotypic characteristic.