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analysis:evolution:nature_vs_nurture

Nature Versus Nurture

What causes poverty?
What do we mean by cause?
Clarify innate, nurture Nurture implies action by parent, teacher, etc. Randomness isn't nurture, though it may be someone's responsibility to protect from random effects, if possible. Acts of the child himself or of other children also aren't nurture, since they aren't properly responsible. Environmental multiplier
What is the right way to do causal accounting when causes act in parallel?
- intuition is that there is no clearly right answer.
- if the crucial property of causality is the possibility of other outcomes in the absence of these factors, and all are preconditions, (necessary) then it does make sense to say that both are causes.
- I'd say that the ease of modification of a precondition isn't usually relevant to whether it's a cause, though that's an obvious practical consideration.
- if you had an “or” precondition (multiple sufficient causes), then that is a bit odd, but if you consider moral responsibility, of two people who shoot the victim, we say both are equally responsible.
- delta nurture + delta nature is “or” like, but the outcome isn't discrete. This quantitative aspect doesn't show up in simple moral thinking of a criminal aspect, but could be seen like civil damages. If A and B were supposed to do some amount of work, and didn't deliver, then we would usually think it fair if their liability corresponded to what they were supposed to have done. Morally they're equally at fault, but one owes more than the other. When additive, it does seem to make sense to say cause is proportional to contribution. But does the multiplier theory mean a nature*environment interaction? It's a positive feedback. Gene environment correlation.
- heritability has looked at genes*environment? But this would be non shared environment?
- moral responsibility isn't exactly the same as causality, anyway. What does the environment need to be like to have a multiplier? Competition, or even just being nonuniform. The only thing that would clearly prevent a multiplier is an environment where the outcome would be completely unaffected by any sort of behavior. In other words, behavior has no consequence at all, at least w.r.t. the outcome. Consider f(g, e) = Ag + Be + Cge
Mathematically, we'd be happy to say that if one term dominates, then f is mainly that term. We might drop the others, as an approximation. In a sensitivity analysis, given particular levels of variance in g and e, we could attribute output variance to one factor. Of course with more general nonlinearities it gets complicated, but here it's just variation / mean, for each factor. We are really talking about the variance for the additive terms too, but the A/B ratio comes into play then. Of course models like these are ludicrously simple compared to the thing modeled, but that doesn't mean they can't give some insight. Is heritability interpretation tricky because it has to do with accounting for variability, and not the mean? Caring about difference is intuitive. It isn't even clear to me what this critique supposes the misleading naive interpretation is. Obviously there's an genetic explanation for the mean too (genetic similarity). Another incorrect critique of heritability is that it entirely fails to account for SES effects such as wealth and parental education. There's room for dispute of whether the accounting is correct, but this is exactly what heritability is trying to do. Generalizing beyond the sample does require an argument of sufficient similarity. This is the “between group comparison” problem. Cultural differences could also affect heritability. For example individualistic western (WEIRD) cultures could increase heritability of behavior because social conformity pressure is reduced. A liberal culture allows individuals to pursue their behavioral inclinations to a greater degree, increasing the diversity of outcomes, and increasing multiplier effects. If you just gave poor people enough to bump them above the threshold, would that end poverty? Not to get carried away here, but you do need to consider our fuzzy intuitions about causation. Suppose we made a causal budget for poverty:
% interaction with intentional adults (nurture)
% interactions with children and irresponsible adults.
% economic opportunity
% personal decisions (free will)
% other bad luck But aren't your personal decisions influenced by your genes, how you were raised, and community norms? The same of is true of your parents, of course. So at some level this gets into free will. Of course social determinism is no more plausible than genetic, but it interesting to see the connection with free will, and the nearby responsibility. But that's blaming the victim, of course, and so off pretty much off limits. Events don't happen for a reason, but things survive for a reason. You can see why poverty survives. We ask the cause because we want to know whom to blame, or we wish to change it by breaking the causal chain. But any enduring system has a mesh of positive and negative feedbacks that maintain it. Poverty isn't a new problem. An attractor. History of social class? Always present in states. Maybe in some tribal agrarian and herding groups. Either a herd or land is capital, so you get wealth variation, even without hierarchy. People who are unemployed or under employed aren't effectively exploited by the economy. Then there are those working poor who often have more than one job, and are “exploited”.

How do we get to be who we are? Taken literally, “nature versus nurture” asks whether something about us was within us even from when we were a child, or if it was caused by nurturing or negligence by the adults who were responsible for our care.

To what degree is human behavior either genetically determined or established by culture? This point is strongly contested because it has political implications. If human behavior is entirely a consequence of culture, than bad behavior such as violence, greed and competitiveness is a consequence of bad culture, and humanity can be arbitrarily perfected by altering culture somehow. If humans are instinctively selfish, greedy, competitive and violent, then perhaps we live in the best of all possible worlds. A “nature” stance is seen as conservative and a “nurture” stance is felt to be progressive or liberal.

What Do We Think?

Since 1900, a view widely promoted by intellectuals is that (in effect) there is no such thing as human nature. That is, if there are any human behavioral instincts, they play so little role in modern life as to be irrelevant. The view that human behavior is entirely socially constructed peaked during the 1970's. Since then, threads of research have come together to make clear that the human mind is not a blank book at birth. For some aspects of mind the innate structure is sort of a first draft, while for others it may only be an outline.

  • Twin and adoption studies have shown that important differences between individuals (such as personality and intelligence) are largely hereditary, with the family environment having significantly less effect. See Behavioral Genetics.
  • Clever experiments on infants have show that many capabilities that we all share in common, such as basic physics understanding (objects don't pass through each other) are present from a very young age, and individual differences such as anxiety level can also be detected. See Descarte's Baby.

So it does make sense to say that humans (in general) naturally behave in certain ways and that each individual differs from others in how they naturally behave. Furthermore, behavioral researchers in psychology, anthropology and economics have developed theories about these human universals and individual differences that clearly show these ideas are extremely important for human self-understanding. They are important because evolution offers scientific narratives relating to basic human behaviors that concern every living human, issues such as cooperation, selfishness, competition, and the conditions that can be expected to promote mutually beneficial cooperation, and the many faces of social inequality. See Cheating, Social Conflict, Cultural Evolution, Individual Differences and Fairness and Hierarchy.

We now know that the theories that all humans have equal mental potential and that pretty much everything is determined by the environment are wrong. But…

So what?

  • The theory that all humans are equal never made any biological sense because evolution needs variation to work.
  • This supports pre-modern popular understandings of intelligence and personality that were never really displaced in popular awareness.
  • The equality theory is substantially technically correct and is morally correct. The fact remains that all humans are very similar to each other and we should strive to give everyone equal opportunity to develop whatever their potential is.

See also: Nature versus nurture, Cultural universal

Discussion

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analysis/evolution/nature_vs_nurture.txt · Last modified: 2014/01/04 00:37 by ram