Nature vs Nurture - who the hell are we?

The Atheist

The Grammar Tyrant
Joined
Jul 3, 2006
Messages
36,409
What are we?

Are we the product of our environment/genes, our upbringing, or both? If both, in what ratio does nature vs nurture work out? Do good parents necessarily bring up "good" kids? Can people overcome a genetic predisposition to non-mental-illness issues?

Lots of questions and I've hardly scratched the surface even!

This thread has come into existence as my family grows and I ponder the answers to the above. The main thrust for my interest has been the taking in of a troubled 15-year old last year. He is almost exactly the same age as my elder son and the two have been together since joining the same daycare at age three months. their upbringings have been remarkably similar, with the big difference that while my boy was primarily living with his mother, he did stay with me every weekend. His friend didn't see his father until he was 10 or 11.

While my chap has worked along the path of true righteousness, passing his school exams, etc., he has also been busted for shoplifting, so has had personal moral issues to deal with. The other one is a tearaway, graffiti-smearing, boozing, dope-smoking, 30-a-day-cig-smoking, aggressive little prick. I felt that living in our house, with clear rules and supervision, he would straighten up. (Without blowing my own trumpet, I am an extremely effective motivator - I'm a professional motivator and give motivational seminars as part of my operations. I can't be too bad, because I'm not free and they keep bringing me back!) I had no trouble motivating this young lad to work hard and try hard. What I couldn't motivate him to do - despite he himself knowing how wrong, stoopid and little dicked it all was - was to stop breaking the fugging law!

We have a former Cabinet Minister in NZ who grew up in the Kiwi equivalent of a trailer-park, yet managed to work his way into a senior position in the government. His brother is still in jail for double homicide. They both grew up in identical circumstances yet have ended up at opposite ends of the spectrum.

Opinions?
 
Last edited:
Are we the product of our environment, our upbringing, or both?
Yes. And genetic make up too, among other biological factors.

If both, in what ratio does nature vs nurture work out?
If I had to put a number to it, I'd guess about 80% nature, and 80% nurture.

Do good parents necessarily bring up "good" kids?
No.

Can people overcome a genetic predisposition to non-mental-illness issues?
Depends on what the genetic predisposition is for. For example, there are some 300 to 400 genes known to have an influence on the development of obesity. But obviously it will not develop if someone does not eat more than s/he needs.

I'm don't know why you single out mental illness issues.
 
My opinion is that the question you pose (nature v. nuture) is unanswerable at this time.

Worse, it is ultimately unanswerable because there are too many variables that (scientifically speaking) cannot be controlled.

As a parent whose kids are grown, I have often wondered what I did right and wrong to shape who they are now. My conclusion is damn little. I've read "tough love" sites where parents talk about how they did all the "right" things like setting rules, being consistent, etc. and yet the kids turn out to be turds.

Other parents (and I include myself in this category) were not very good in the parental role and yet the kids turn out ok.

There are so many influences that it is impossible to know what the determining factors are. Genetics. Environment. Peers. School. Religion (or the lack, thereof), etc.

Take the last, for example. I raised two kids. Daughter is a born-again Christian. Son has no interest in religion at all and thinks I'm a bit of a loon for my militant, outspoken atheism. You tell me what conclusions can be drawn.
 
My opinion is that the question you pose (nature v. nuture) is unanswerable at this time.

I agree, which is why I'm asking it!

You tell me what conclusions can be drawn.

That carries on from the previous, I think - it's pretty hard to draw conclusions because we don't know.

To me, it's a bit like The Ultimate Question of Life, The Universe and Evereything; I'm not even sure what the right question is. Finding genes which affect human nature to the extent of an in-built morality isn't one of the easier tasks you could come up with.
 
Yes. And genetic make up too, among other biological factors.

Duh! Thanks! I didn't realise until you put that in that I'd made it ambiguous by using "environment" when I meant the physical factors which shape us - icluding genes.

Fortunately, it was early enough to edit it.

Cheers - saved me looking like a dork for a whole thread.

If I had to put a number to it, I'd guess about 80% nature, and 80% nurture.

That's my gut instinct as well. Obviously, intelligence comes into play and smart people generally have smart kids. The bad news is that not-so-smart ones tend to have not-so-smart kids.

Depends on what the genetic predisposition is for. For example, there are some 300 to 400 genes known to have an influence on the development of obesity. But obviously it will not develop if someone does not eat more than s/he needs.

I'm don't know why you single out mental illness issues.

I'm trying to separate out those issues which can be treated by chemical means - schizophrenia, bi-polar, ADD/ADHD [?] from those which can't quite so readily. Things like motivation, honesty, reliability, tendency to anger/temper, things which make people who they are.

If a kid is brought up to be honest and faithful, in a loving home environment, what them makes that kid go completely wrong? We know it happens, we blame genes and the physical environment, but is it? Is there a violence gene which makes people predisposed to violence? Hell, should we be working towards eugenics? Find and eliminate those genes which cause humans to do harm?
 
The way I see it nature sets the top and bottom limits and the "default" and nurture takes care of the details. With really terrible nurture the bottom can be very low.
 
Is there a violence gene which makes people predisposed to violence?

I don't know, but I guess it's perfectly possible. Of course societies are not ready to accept this because it may lead to cascading developments that we wouldn't know how to handle.
 
The Atheist, I'm afraid that I don't have much insight into your situation, but I commend you for trying (and for caring) for such a difficult child. I can't imagine how difficult it must be to try so hard to set him on the right path only to see him take another. I realize that many parents have to face that. It just makes me sad - particularly when I see so many parents who DON'T try. Just remember, you can only do so much.
 
The Atheist, I'm afraid that I don't have much insight into your situation, but I commend you for trying (and for caring) for such a difficult child. I can't imagine how difficult it must be to try so hard to set him on the right path only to see him take another. I realize that many parents have to face that. It just makes me sad - particularly when I see so many parents who DON'T try. Just remember, you can only do so much.

Thanks for that! But it is just an anecdote to the main question.

Do we have any resident behavioural science experts?
 
I'm afraid a behavioural science expert won't really help, there just isn't an answer yet. We know for absolutely sure that both nature and nurture are involved, but exactly how much and at what times are not even close to being known.
 
I don't know the answer to your questions, but to add some hope into the equation, my younger brother got off to a horrible start, but somehow just "grew up" and got his act together once he turned 19 and was living on his own. He's still got some issues, but I seriously thought he was just doomed when he was 15-18. But when he was 19 he moved to a different state, got his own apartment, and has basically stayed out of trouble since then, and that was 5 years ago.
So I guess the moral of the story is, some people don't quit walking the tightrope until they know there's absolutely no safety net below to catch them should they fall?
 
I think that there are probably such complex interactions in the variables of nature and nurture that it would probably make drawing percentages impossible. Although, I suspect that nature sets the limits on what nurture may accomplish. For example, one's nature may set time limits on how long nurture has to make changes. Some people may to be able to change behaviors quite easily while younger, but lose this ability as they grow older into adulthood. These people may simply keep the prominent behaviors they has while shifting into this stage, and may not be able to deviate much from there. Others may find it easier to change their behavior in accordance to the type of nurture environment they inhabit for their whole life. Ultimately, I think this is one of those interesting questions that may never get answered.
 
I vote 80% nature, 20% nurture.

I just look at what dogs have bred into them. Different breeds for different pruposes. Some are mean, others docile. Some go to fetch in the direction a shot is fired. Others go hide in the opposite direction. And dogs are much simpler than humans.
 
Rather than a relative contribution in an additive manner, I would suggest that it is looked at as an interaction. Taking extreme examples - when everyone is exposed to much the same environment, then any variation comes from the genetics; when everyone has the same genetics, then any variation comes from the environment. Instead of adding to 100, the relative contributions would multiply to 100. Instead of a point on a line, you would be looking at a box in two dimensions.

Linda
 
Part of it can be chalked up to youth. The area of the brain used to determine consequences to actions doesn't mature until the early 20s in men. If he is drinking heavily or using drugs, that growth can be retarded.

Boys with higher testosterone levels can be more rash and aggressive, so there could be a genetic factor, too.


I often wonder about the Nature vs. Nurture. My maternal grandmother ended up raising my sister from an infant. I see a lot of the same behaviors in my mother and my sister that I don't have and wonder if it is because of their similar upbringing.
 
Rather than a relative contribution in an additive manner, I would suggest that it is looked at as an interaction. Taking extreme examples - when everyone is exposed to much the same environment, then any variation comes from the genetics; when everyone has the same genetics, then any variation comes from the environment. Instead of adding to 100, the relative contributions would multiply to 100. Instead of a point on a line, you would be looking at a box in two dimensions.

Linda

That's really deep, Linda. Wow. I think you have to be correct.

It's still too complex to definitively figure out the hows and whys of human behavior, though. There are going to be billions and billions of genetic and environmental factors at play. Even with those situations where strong trends are observed (children who are abused growing up to become abusers, for example) there are always lots of exceptions. So trying to figure out why one person does what they do is basically impossible.
 
Behavioral expression

The way I think about it isn't really any different than how others have just explained it -- but my brain thinks of this idea (nature vs nurture and the resultant behaviors) in terms of behavioral expression. I always wonder does the environment "allow" said genes or behaviors be expressed? The environment in this case could be physical or social.

I don't know if my pitbull mix has the genes and/or behavioral expression that would make her a fighting dog, as others of her breed may be. I never let her be in that type of environment to find out if those behaviors would be expressed. But we can't do the same thing to our kids their entire lives ;)
 
Taking extreme examples - when everyone is exposed to much the same environment, then any variation comes from the genetics; when everyone has the same genetics, then any variation comes from the environment.

But even the extreme examples do not work that way. When viewed in terms of complex systems, even when the genotypes - the system blueprints - are the same, the people - the live running interactive systems - do not react the same way to the same environment, as their internal states are different. Very small differences in previous phases produce unpredictable large-scale changes in later phases.
 
But even the extreme examples do not work that way. When viewed in terms of complex systems, even when the genotypes - the system blueprints - are the same, the people - the live running interactive systems - do not react the same way to the same environment, as their internal states are different. Very small differences in previous phases produce unpredictable large-scale changes in later phases.

Your point is in addition to the point that I was making, in that I think you are talking about chaos - small changes in inputs can lead to widely divergent outputs. My extreme examples were meant to be a thought experiment to convey the idea that not only does variation in one factor (nurture) and variation in another factor (nature) lead to variation in output (behaviour), but that the amount of variation contributed by one factor varies depending upon the value of the other factor. You make the observation (which I agree with) that this relationship may also be non-linear.

Linda
 
I believe it's still the case that the best predictor of an person's behavior is a person who knows them. If you want to know what someone will do in a certain situation, ask their friends. This isn't surprising because of the interest we have in predicting behavior. I don't think abstractions such as the nature/nurture dichotomy will ever lead to better predictions or analysis of human behavior than what our huge finely tuned brains can already do. If such an abstraction were useful, it would be instinctive.
Also I don't like the nature/nurture dichotomy because of the chaotic sensitive dependencies noted above and the difficulty separating nature from nurture. How do we classify breast feeding? Cycles of stress and the immune system? Epigenetics? The effect that stress on the mother has on the baby's fetal development?
 

Back
Top Bottom