Non-Shared Environment

Monday, May 2nd, 2016

Non-shared environment doesn’t just mean schools and peers, Scott Alexander reminds us:

The “nature vs. nurture” question is frequently investigated by twin studies, which separate interpersonal variation into three baskets: heritable, shared environmental, and non-shared environmental. Heritable mostly means genes. Shared environmental means anything that two twins have in common – usually parents, siblings, household, and neighborhood. Non-shared environmental is everything else.

At least in relatively homogeneous samples (eg not split among the very rich and the very poor) studies of many different traits tend to find that ~50% of the variation is heritable and ~50% is due to non-shared environment, with the contribution of shared environment usually lower and often negligible. This is typically summarized as “50% nature, 50% nurture”. That summary is wrong.

I mean, it’s tempting. All these social developmentalists were so sure that the way your parents praised you or didn’t praise you, or spanked you or didn’t spank you, had long-lasting repercussions that totally shaped your adult personality. The underwhelming performance of shared environment in twin studies torpedoed that whole area of study. But at least (these scholars of social behavior could tell themselves) it provided a consolation prize. The non-shared environment contributes 50% of variation, just as much as genes. That means things like your friends, your schoolteachers, and even that time you and your twin got sent away to separate camps must be really important. More than enough there to continue worrying about how society is Ruining The Children, right?

Not necessarily. Non-shared environment isn’t really “non-shared environment” the way you would think. It’s more of a dumpster. Anything that isn’t genetic or family-related gets tossed into the non-shared environment term.

Posted in Science | 1 Comment »

Understanding and Training the Female Shooter

Monday, May 2nd, 2016

Greg Ellifritz shares some things he learned from Lou Ann Hamblin’s Understanding and Training the Female Shooter class:

When measured on a dynamometer, most men have similar grip strength between their dominant and non-dominant hands (as tested in class, my hands differed by only 2 lbs. of force between right and left). Most women have a HUGE disparity…differences of up to 40% are common. Would that knowledge affect how you teach off-handed shooting for a female student? It should.

Female vision is different than male vision. Women have less depth perception, but better peripheral vision than men. It affects how women see the sights on their guns and how far they have to move their head to do an after-action scan.

Shorter-waisted women have difficulty drawing from many traditional holsters. Their body styles change which gear works best for them.

Women are known to be better multi-taskers than men. This can be problematic in firearms training as some women will try to do too much, taking your suggestions very literally. If you give most women a list of 10 things they are doing “wrong”, they will try to work on them all simultaneously and won’t make as much improvement as if you gave them just one or two things to improve at a time.

Because of differing motivational strategies, competition in training will often yield different results between men and women. Most men really enjoy competition and find it valuable. Because most women are motivated more by social connection than by ego gratification, competition may not give the same benefits. Lou Ann suggested using team competitions (where students are partnered up to achieve a goal) when training women. She believes that women will be better motivated to perform if they are trying to help their partner than if they were trying to win some type of individual award.

“Women need details…but only when they are ready for them. Don’t over-explain things in the beginning, but be ready to explain things in much more detail that you ever imagined necessary when she asks for it. But, she won’t ask for the details if she thinks you are a dick.”

Posted in Education, Fitness, Weapons | No Comments »

Kay’s Other People’s Money

Sunday, May 1st, 2016

John Kay’s Other People’s Money argues that the growth in the size of the financial system hasn’t been matched by improvements in the allocation of capital:

He proposes that financial services are not as profitable as some headline numbers would suggest. And he suggests that the replacement of those who are good at meeting clients on the 19th hole with those who were good at solving complex mathematical problems was not always a good thing — sometimes clever people are the problem, particularly in a complex environment.

On that last point:

The organisational sociologist Charles Perrow has studied the robustness and resilience of engineering systems in different contexts, such as nuclear power stations and marine accidents. Robustness and resilience require that individual components of the system are designed to high standards.… More significantly, resilience of individual components is not always necessary, and never sufficient, to achieve system stability. Failures in complex systems are inevitable, and no one can ever be confident of anticipating the full variety of interactions that will be involved.

Engineers responsible for interactively complex systems have learned that stability and resilience requires conscious and systematic simplification, modularity, which enables failures to be contained, and redundancy, which allows failed elements to be by-passed. None of these features — simplification, modularity, redundancy — characterised the financial system as it had developed in 2008. On the contrary, financialisation had greatly increased complexity, interaction and interdependence. Redundancy — as, for example, in holding capital above the regulatory minimum — was everywhere regarded as an indicator of inefficiency, not of strength.

Posted in Business, Economics, Policy | 2 Comments »

An Anecdote from Free Northerner

Sunday, May 1st, 2016

Free Northerner shares an anecdote from his life in Canada:

Recently, I was downtown walking to my truck after an evening out. An aboriginal women in her 30’s approached. She was obviously either somewhat drunk or high (or possibly mentally ill). She could talk clearly and walk straight, but was noticeably ‘off’, she tended to repeat herself and seemed paranoid. I haven’t had enough experience with drug users to determine what she had partook in. She asked me for cab fare. I offered a couple of loonies and twonies ($1 and $2 coins, for you Yanks) in my pocket, but she refused.

She then told me, she didn’t need cab fair, she needed me to call her a cab. She said she was afraid and didn’t trust anyone, but she needed to get back to her hotel. Which was odd, because she was trusting me and I was a complete stranger and probably not especially trustworthy-seeming as I looked exceedingly redneck-prol at the time. She didn’t want to call the cab herself because she was afraid they would be “mean” (her word, but by the intonation of it she clearly meant something darker) to her and would not come for her, but they would listen to me. She repeated herself often as we talked, and at one point even offered me $20 to call a cab (after I was already on the phone and which I did not take).

I phoned a cab, as she continued on. She repeated multiple times she was afraid of dying and didn’t trust anyone. She didn’t want to be downtown because bad men might do something to her. (As she talked to me, a strange man with a redneck beard, a heavy metal shirt, and camo jacket), but didn’t want to phone a cab herself, because she didn’t trust them.

The call finished, a cab was coming. She thanked me, repeatedly and profusely, with obvious relief in her eyes. Then offered a handshake, which I took and she held for much longer than normal. She spent the next minute or two switching between thanking me and saying she was afraid. In the middle of her ramblings, she said something in the neighbourhood of ‘I knew I could trust you because you’re white’.

[...]

For those who aren’t from Canada, aboriginal-white relations are akin to black-white relations in the US. Our ghettos are aboriginal neighbourhoods (although, not as bad as American ghettoes), aboriginals have high poverty rates, and aboriginals make up a disproportionately large number of criminals.

[...]

Despite all this, a white man was the one this women turned to when she was afraid.

Posted in Policy | 3 Comments »

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