Nature v Nurture

[James Hannam]

Hi all,

This is a discussion on nature and nurture from this blog post: bedejournal.blogspot.com/2008/06/parents-versus-peer-groups.html

Let me start by saying that personal experience is useless with a question like this. There is a huge literature on how humans can foll themselves and how bad we are at correctly connecting cause to effect. That is why we need the scientific method and why science was so incredibly difficult. By previous blog post on how bad the ancient Greeks were at science is related to this point. Aristotle never managed to move beyond a direct correlation between observation and underlying cause. Consequently, he was wrong about almost everything. Of course we need large scale objective studies. And they trump anecdote and experience every time.

Let me also say that parents and teachers remain important. They may not be able to mold personalities, increase intelligence or (in that hackneyed phrase) foster a love of learning. But they impart knowledge, they can provide a healthy diet (diet remains the essential environmental factor which can affect characteristics), they should determine boundaries and discipline, and they help determine how happy children are. That final point, I'd say, although subject to genetic limits, is probably the most important of all.

Finally, we are talking here about outcomes, not immediate behavior. You can change a child's behavior in the short term very easily by intervening. But in the long run, that does not effect their characteristics. Children deprived of their mothers get upset (this I know very well from experience of my three year old) but this will not turn her into an introvert. It will just make her miserable.

By the way, this article explains some of the recent research in this area and what it means. Please read it before commenting on this thread:
pinker.wjh.harvard.edu/articles/papers/nature_nurture.pdf

Best wishes

James

[Richard]

Dear James,

While I am a bit dismayed to find the degree to which the research Pinker cites seems to diminish what the parents can do to influence the moral life of the child when grown, I do firmly believe that human beings have a nature which is powerfully influenced by biological factors. The idea that we have no nature except to be the creatures who invent themselves has always seemed to me to be delusional. Pinker's essay is lucid, subtle, and largely persuasive to me.

Two key questions occur to me, and I would like to know your thoughts (or the views of others):

1. Is there any use in parents attempting to morally educate their children?

2. Is there any place for human freedom in the interplay between biological and environmental agents shaping the person?

Best,

Richard Moorton

[Mike D]

Pinker states in the paper:

"Behavioral geneticists have...[through twin studies]...discovered that in fact virtually all behavioral traits are partly (though never completely) heritable. That is, some of the variation among individual people within a culture must be attributed to differences in their genes."

A fairly non-controversial conclusion, I would have thought. Though I would be interested to know what 'behavioural traits' means in the context of psychological studies - is this what a person has a tendency towards or what they actually do, or does it in fact cover both? For example, I have a tendency towards procrastination, but by self-discipline manage to stop my house falling down and keep my bills paid etc: is there some part of this behaviour that is covered by the concept of 'behavioural trait'?

Mike

[James Hannam]

Richard,

Thanks for your support. I'm not sure things are as dismal as you think, though. Parents still have lots to do even if we can't mold our childrens personalities or make them clever.

To answer your questions as best I can:

1) Yes. Much of morality is knowledge rather than instinct. We learn about right and wrong as well have having in-built ethical machinery. It's the difference between hardware and software, if you like. You need both to be functioning moral agents.

2) I certainly think so. We seem to inherit about half of our mental characteristics. The other half is not, as far as we can tell, caused by unbringing. Scientifically, it appears essentially random. But it could just as easily be self-determination which would look the same as randomness in a statistical study.

Best wishes

James

[James Hannam]

Mike,

The radical bit of Pinker's is not that genes have a roll in behavioral characteristics, it's that upbringing does not. That is where I've been copping some flak.

What I said about self-determination above may well be how you can overcome your procrastinating tendencies. Other people might decide they can;t be bothered. As I find freewill undeniable, there must be a choice. But there is no reason that statistical studies would pick it up.

Best wishes

James

[Niall]

I've read the Pinker article. To be honest, I agree with most of it. I'm just not sure to what extent you agree with it. Take for instance the following:

There is an aspect of this statement that indeed is worth stressing. Genes do not determine behavior like the roll of a player piano. Environmental interventions– from education and psychotherapy to historical changes in attitudes and political systems–can significantly affect human affairs. Also worth stressing is that genes and environments may interact in the statistician’s sense, namely, that the effects of one can be exposed, multiplied, or reversed by the effects of the other, rather than merely summed with them. Two recent studies have identifed single genes that are respectively associated with violence and depression, but have also shown that their effects are manifested only with particular histories of stressful experience.

I find that hard to reconcile with your statement that:

I've realised that the fact that nurture and peers are irrelevant to characteristics is probably the most important scientific discovery of the last fifty years.

Of course, you seem to be using a definition of characteristics that I'm not entirely familiar with. You claim that characteristics include

intelligence, extroversion, shyness, propensity to addiction, laziness, mathematical ability and optimism

Just to seize on one of these characteristics, laziness is a useless term practically. It is never really useful to say that somebody is lazy, rather that they are unmotivated to perform a certain action. Motivation is a factor that can be manipulated. Different people respond differently to different rewards. Find the write reward, and you can motivate seemingly lazy individuals to do a large number of things.

If we say that somebody is lazy, what we actually mean is that under typical circumstances, they are less motivated than most people to engage in certain activities. Yet, were we to tweak the environment to their preferences, this characteristic, would not present itself. If laziness is heritable, it is only heritable under typical circumstances.

In regards optimism, it has been shown that in pessimism is a major factor in depression. However it has also been shown that cognitive behavioural therapy which seeks to change thought patterns so as to eliminate this pessimism can be very affective.

Intelligence is something that is hard to quantify. You claim that intelligence is an innate characteristic, or at least that it largely innate. However, the research that I'm aware of refers largely to IQ, which is very much an imperfect measure. Especially as we get older, crystalised knowledge stores becoming increasing important. Also, certain decision making and problem solving techniques, which most people do not normally acquire, can be taught to individuals so as to improve their abilities when completing tasks of this nature. It may be that it is biological factors that ultimately set the limits of our abilities, but I doubt there is any area of life in which we have maxed our potential.

When we talk about how personality is determined, it's important to notice that there are cultural differences in personality type. And indeed when talking about characteristics we need to be careful. For instance, one might suggest that promiscuity is a characteristic. One might also suggest that extroversion was a personality characteristic. However, while it has been found that extroversion is linked to promiscuity in many cultures, it is not the case for all cultures.


www.ac.wwu.edu/~culture/Schmitt.htm

This raises interesting questions. When is a characteristic a characteristic? There seems to be evidence to suggest that different personality traits express themselves different cross-culturally, but at what point does one make a distinction between a different expression of a personality trait and a different personality trait?

Finally, we are talking here about outcomes, not immediate behavior. You can change a child's behavior in the short term very easily by intervening. But in the long run, that does not effect their characteristics. Children deprived of their mothers get upset (this I know very well from experience of my three year old) but this will not turn her into an introvert. It will just make her miserable.

I'm curious as to what you mean by outcomes here. When does an immediate behaviour become an ultimate outcome? Many children who are deprived of their mothers become upset, but not all, and not all to the same extent. Their reactions can be used to describe the child's attachment style which predicts many future behaviours, attitudes etc. and which is the result of parenting style.


www.sonoma.edu/cihs/asd/pdf/Howard%20et%20al%202005.pdf

en.wikipedia.org/wiki/Attachment_in_adults#Attachment_styles

[Mike D]

James,

My understanding of the paper was that environment (as opposed to heredity, if indeed they can be opposed) does have an effect, but that any effect from upbringing (i.e. parents/family) was swamped by the effect from 'peer group'. Was that your understanding? I suppose this could be interpreted as meaning that good upbringing *could* have an impact, but only if it is 'backed up' by offspring moving in the right social circles. I don't deny Pinker's statistics, but my anecdotal experience (my own and my children's) is that upbringing does have an effect - this could either mean that the effect is hard to quantify or that I am fooling myself!

Mike

[rfmoo]

Dear James (et al.),

Thanks for your answer. I find it heartening, and I learned from the other posters. I do think that we need to consider a few other factors. For one thing, even in the age of the nuclear family, parents can have a big influence on the constitution of the peer group. I've seen relatives of mine very carefully craft the peer groups of their kids (who were responsive because their parents were reasonable, loving, and wise) and believe me it shows in the final product.

Also, we need to be wary of the chasm between the parents and peer group that Pinker's thinking suggests. In our Western, individualistic culture, this is a very real phenomenon. It is as though kids have two lives, and they are more willing to tell their friends about their parents than vice versa ("but EVERYBODY'S doing it"). I have seen it at work as a teacher of many years experience. I currently teach at a good liberal arts college in the US, and the peer group is AT LEAST as powerful as the teachers in shaping minds and habits, and, if I listen to the testimony of some of my brightest students (one now a colleague of mine, happily), perhaps more so.

But in other cultures, there is much more continuity between the family and the peer group, and the family has more power over the peer group. Consider countries in which tradition is strong, and the senior family members remain very powerful in the world of the community and the lives of the offspring as long as the elders live. I suspect that that changes the calculus quite a bit.

But in general I agree with you and Pinker about the power of the genes and the power of the society at large in shaping the personality of the person. But to judge from my own experience, there is something in us that can say yes or no to at least some of the above.

Best,

Richard Moorton

[James Hannam]

Hi Niall,

Thanks for joining us and sorry about the delay in replying.
Let me first briefly analyse the Pinker passage you quoted. Pinker said,

“There is an aspect of this statement that indeed is worth stressing. Genes do not determine behavior like the roll of a player piano. Environmental interventions– from education and psychotherapy to historical changes in attitudes and political systems–can significantly affect human affairs.”

Note he says ‘affairs’ here. Not personality or even (though he arguably could have) behaviour. Take violence. Even a gentle soul may get violent when provoked. A less gentle soul requires less provocation. Thus environment affects violence. What is not the case is that if you bring someone up to abhor violence, they will require more provocation as a result.

“Also worth stressing is that genes and environments may interact in the statistician’s sense, namely, that the effects of one can be exposed, multiplied, or reversed by the effects of the other, rather than merely summed with them. Two recent studies have identifed single genes that are respectively associated with violence and depression, but have also shown that their effects are manifested only with particular histories of stressful experience.”

Another good example is the genes that predict addiction. Some people become alcoholics much more easily than others. Suppose two men each loose their wives. Both hit the bottle. So far, it is all environmental. But only one has a genetic propensity towards alcoholism so only one becomes an alcoholic.

All this is entirely consistent with my statement: “I've realised that the fact that nurture and peers are irrelevant to characteristics is probably the most important scientific discovery of the last fifty years.”

Turning to characteristics, you wrote

“Just to seize on one of these characteristics, laziness is a useless term practically. It is never really useful to say that somebody is lazy, rather that they are unmotivated to perform a certain action. Motivation is a factor that can be manipulated. Different people respond differently to different rewards. Find the right reward, and you can motivate seemingly lazy individuals to do a large number of things.”

Of course you can. But want you can’t do is bring them up in such a way that they require less or different motivations to those they require anyway. Suppose I require a kick up the backside to work hard rather than being a self starter. That is because of a characteristic I have in contrast to another person who might be a self-starter. These things, I’ve said, are not changed by my upbringing. I react to the immediate stimulus (in this case motivation) but that cannot change the kind of person I am.

“If we say that somebody is lazy, what we actually mean is that under typical circumstances, they are less motivated than most people to engage in certain activities. Yet, were we to tweak the environment to their preferences, this characteristic, would not present itself. If laziness is heritable, it is only heritable under typical circumstances.”

This paragraph is a category mistake. The heritability is prior to the environment. You can’t change it by tweaking things. You can change how people react by changing their circumstances.

“In regards optimism, it has been shown that in pessimism is a major factor in depression. However it has also been shown that cognitive behavioural therapy which seeks to change thought patterns so as to eliminate this pessimism can be very affective.”

Indeed. Depression is an illness which is, luckily, treatable. But my long term experience of people prone to depression is that you can treat particular instances but you can’t make them less prone to it in the future.

“Intelligence is something that is hard to quantify. You claim that intelligence is an innate characteristic, or at least that it largely innate. However, the research that I'm aware of refers largely to IQ, which is very much an imperfect measure.”

Agreed. We haven’t got a good way to measure intelligence or to distinguish innate intelligence from acquired knowledge. Certainly the later is important and not genetic. But how well you can utilise it is genetic. You can’t increase your maximum potential braininess by going to the right school or being hothoused or anything else. I could never, ever have been Einstein.

“When we talk about how personality is determined, it's important to notice that there are cultural differences in personality type. And indeed when talking about characteristics we need to be careful. For instance, one might suggest that promiscuity is a characteristic. One might also suggest that extroversion was a personality characteristic. However, while it has been found that extroversion is linked to promiscuity in many cultures, it is not the case for all cultures.”

I think the explanation for this is quite simple. Promiscuity is always measured by number of sexual partners. Imagine, for the sake of argument, that all men have just as much desire to get laid as often as possible. In our society, extrovert men get more girls because they sell themselves better. So they get labelled as more promiscuous whereas they are actually just more successful. But in a more traditional society where women are not allowed to pick their partners and marriages tend to be arranged, the extrovert guys loose their advantage. So there is no link between being promiscuous and being an extrovert. There is no difference needed in the personality data.

From: www.ac.wwu.edu/~culture/Schmitt.htm “The results from the Middle East strongly supported the "Infidelity-Promiscuity Personality Difference" hypothesis. Relationship Infidelity was related primarily to low agreeableness and low conscientiousness, whereas Sexual Promiscuity was related only to high extraversion in Turkey, Lebanon, and Israel.”

So in the Middle East, being extrovert only helped get girls in the most westernised liberal societies. The rest of the study appears at first blush explainable in similar ways.

“This raises interesting questions. When is a characteristic a characteristic? There seems to be evidence to suggest that different personality traits express themselves different cross-culturally, but at what point does one make a distinction between a different expression of a personality trait and a different personality trait?”

Actually, I’d say the most interesting question is why researchers are still stuck in the old paradigm as so much evidence about the importance of genes mounts up. Genetics isn’t even mentioned in the article you referenced. It is, by my first law of behaviour studies, useless.

Finally, for reasons I explained in the blog posts linked below, I think attachment theory is bogus.

bedejournal.blogspot.com/2008/03/rise-of-attachment-theory.html
bedejournal.blogspot.com/2008/03/problem-with-attachment-theory.html

I hope this helps explain my views a little more clearly.

Best wishes

James

[David Taussig]

James,

I don't know if you have seen the results of this twin study from Sweden but thought you might be interested.

www.qmul.ac.uk/news/newsrelease.php?news_id=1075

David

[James Hannam]

David,

Thanks for the link to the article. Nice to see more evidence coming in that upbring has little effect. What is most interesting is how little genetics matters to female homosexuality. Almost as little as upbringing.

BUT, does the fact that being homosexual makes you less likely to reproduce skew the results? I don't think it does but can't quite put my finger on the exact argument.

By the way, the article talks about 'non-shared environment'. This is code for "we haven't a clue/could be completely random". Basically non-shared environment is what's left after you take account of shared environment (family and upbring) and genetics. Researchers assume an unexplained factor must be environmental but have no real evidence for this or much clue what it might be.

Best wishes

James

[David Taussig]

Regarding the missing non shared factors in behaviour I wonder if these could be acquired DNA changes (that occur after birth; these could be different between identical twins).

I don't know if anyone has looked at brain DNA to see if there are any acquired changes in the DNA sequence analagous to the changes that occur in T and B cells ...ie the somatic hypermutation and VDJ rearrangements that occur randomly and give the T and B cells their specificity.

If these occured in a subset of brain cells whole brain DNA analysis might miss it.

David

[James Hannam]

Here's a story from the BBC showing that (at least as adults) how happy we are is generally fixed rather than dependent on our live's course.

news.bbc.co.uk/1/hi/health/7502443.stm

A bit more evidence of how little environment can matter.

Best wishes

James