https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4009388/
http://sci-hub.tw/https://doi.org/10.1016/j.labeco.2012.11.0...
I can't now find the (also Swedish I think) study I remember, which managed to look at families who'd got suddenly rich between the 1st son & the 2nd son.
This of course is an amazing natural experiment to see if genes or parenting is the cause of important personality traits.
The study "found that an identical twin reared away from his or her co-twin seems to have about an equal chance of being similar to the co-twin in terms of personality, interests, and attitudes as one who has been reared with his or her co-twin. This leads to the conclusion that the similarities between twins are due to genes, not environment, since the differences between twins reared apart must be due totally to the environment."
So, yes, genes clearly matter.
This is a very unfashionable finding currently in the US, but the science is clear.
Families who adopt are not necessarily representative of the wider population.
The science is not really that clear. Tyler Cowen [1] refers us to Jay Joseph [2] who refers us to other critics of "twins reared apart" ("TRA") studies:
Critics, however, have pointed to several key methodological problems with TRA studies (TRA study critics include Farber, 1981; Joseph, 2001, 2004, 2010; Kamin, 1974; Kamin & Goldberger, 2002; Lewontin, Rose, & Kamin, 1984; Taylor, 1980). These problems include (a) the doubtful “separation” of twins, who frequently grew up together and had contact over much of their lives, (b) similarity bias in the methods of MZA identification and recruitment, (c) the questionable status of “intelligence” and “personality” as valid and quantifiable constructs, (d) the failure of the MISTRA researchers to publish or share raw data and life history information for the twins under study, and (e) the impact that the researchers’ bias in favor of genetic interpretations may have had on their results and conclusions.
and continues:
While these and other issues are important, the main problem with TRA studies such as Bouchard’s MISTRA is clear: the investigators used the wrong control group (MZTs). By using MZTs as controls, they failed to control for several key environmental factors shared by both MZA and MZT pairs (see Joseph, 2004; Rose, 1982). Environmental influences shared by both MZAs and MZTs include but are not limited to the following:
• They are exactly the same age (birth cohort).
• They are always the same sex.
• They are almost always the same ethnicity.
• Their appearance is strikingly similar (which will elicit more similar treatment from the social environment).
• They usually are raised in the same socioeconomic class.
• They usually are raised in the same culture.
• They shared the same prenatal environment.
• Most studied pairs spent a certain amount of time together in the same family environment, were aware of each other’s existence when studied, and often had regular contact over long periods of time (Farber, 1981; Kamin, 1974).
So maybe twin studies aren't the slam dunk they are often presented as.
[1] http://marginalrevolution.com/marginalrevolution/2011/02/wha....
[2] http://jayjoseph.net/yahoo_site_admin/assets/docs/Claims_and....
Also referenced by Cowen:
http://journals.cambridge.org/action/displayAbstract?fromPag....
Yes, but it does suggest it is a possibility. I thought it was a common belief that genetics play a part in addiction, and mental illness. I do agree that socioeconomic factors are most likely the biggest contributor, the movie Trading Places convinced me of that at a young age. I just think it would be foolish to dismiss genetics completely.
This is an interesting thing to admit. What is the evidentiary value of a fictional movie?
Family trades are a big thing but even absent that social status is highly heritable in every society Gregory Clarke looked at in England, the United States, Sweden, India, China, Taiwan, Japan, Korea, and Chile. A doctor’s children may have divergent status but their children and grandchildren will look more similar, on average, as n increases the variance will decrease.
You're 100% spot on that it's not biological, but more than likely just a result of the other factors associated with class and access to wealth.
Yes, nurture matters, but so does nature. Declaring this settled science "an attempt to justify hate speech" is laughable.
In particular, the following factors are both quite correlated with crime (and in a way where it's reasonable to assume causation) and also are known to be somewhat heritable:
a) mental disorders such as psychopathy;
b) being prone to addiction;
c) general impulse control and risk-seeking behavior.
Given the available evidence, it would be wrong to assume an absolute lack of relationship between your genes and propensity to crime, there clearly is some (though not necessarily large) genetic determinant for crime - all other things being equal, some newborn babies are a bit more likely than others to go on and commit crimes when they grow up.
My issue isn't with the claim that there is likely some genetic connection to crime. Clearly, in some extreme cases, there is. My issue is with the extrapolation from extreme cases and from very un-settled science to broad claims about genetic determinism (and supposed unwillingness of others to entertain those claims).
† I'm not saying you're using racist rhetoric, I'm saying you're using rhetoric that is also leaned on by racists; for instance, "black people have a genetic predisposition to high time preference".
These personality traits (like most personality traits, really) have a clear genetic component. I would consider this as settled science. For a single example, studies show that varieties of dopamine receptor D4 gene (DRD4) influence financial risk-taking propensity, impulsivity (e.g. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1781951/), and pathological gambling. As far as we assume causal relationship from impulsivity and pathological gambling to risk of crime (likely there are studies for that, but I'm not going to look now, this seems a reasonable assumption), this implies that this is one more (of many!) genetic factors that have some (small) influence on the likelihood of committing crimes.
Coming back to your specific objections, can you elaborate the what your issue is with "broad claims about genetic determinism" here? I'm not seeing any serious claims of actual genetic determinism (i.e. that it's "all nature") in this thread, I'm only seeing objections to a "no nature" argument, claims that there is no genetic component. The current established scientific opinion is that the vast majority of personality traits are determined by genetic factors (including e.g. epigenetics) and environmental/social factors and individual variation, with all of these influences being intertwined and each of them constituting a major part of the influence. And this is not limited to extreme cases (i.e. particular genetic disorders), but to all the normal variation of human behavior.
But there are a lot of inherited traits that absolutely could lead one to be more likely to get involved in crime. Things like fight vs flight response, risk tolerance, extroversion/introversion, etc.
Saying "You're 100% spot on that it's not biological" is really absurd. Nothing about humans is 100% non biological. That absolutism is exactly blank slate theory.
We can't close our eyes and ears and pretend that genetics plays no role in society (including issues of violence, crime, mental health, addiction, etc).
Again, the context of the thread is that appeals to genetic determination are "in the worst case" coded appeals to racism. And, obviously, they often are. You haven't engaged with that argument, but rather constructed a straw man to attack.
What is true is that if you want to ruminate on possible genetic links to criminality, you're probably need to be careful, because you're treading on ground that has very much been staked out by racists over the last 100-or-so years. Don't get angry at people who point that out to you; get angry at the racists. Or, I mean, move on to some other, less freighted argument.
I have never met my Grandfather and Uncle that were thieves and another was a sex offender.
I do however like mischief and I love the feeling of thieving stuff. I used to work in Gambling and absolutely loved the idea of taking money from other people. I also have a lot of affiliate sites and I feel like I am stealing that money.
However to say it is 100% one or the other is also garbage. It is another nature vs nurture argument.
Also "Hate Speech" is another way of saying I don't have an argument. It is just a way of saying "You are bad because I don't like what you are saying". This term is destroying my country (people in the UK have been imprisoned because they have posted rap lyrics on facebook).
https://reason.com/blog/2018/04/23/she-posted-rap-lyrics-to-...
https://www.telegraph.co.uk/news/worldnews/northamerica/usa/...
Or, it is because biological and genetic factors aren't as powerful at predicting crime as other factors. The idea that crime runs in families indicates a biological factor in crime is nonsense. Families and children that start in lower deciles of wealth are likely to stay there. Social mobility is awful.