Behavioral Genetics

[Laura]

Yet another veeeerrrrry interesting find today:

The Behavioral Genetics Page

This page is to make an easy to use (and easy to share) central repository for my posts on the science of behavioral genetics. This is fundamental reading for anyone interested in HBD – indeed for anyone interested in the human sciences in general. The Five Laws of Behavioral Genetics The five...

www.unz.com

This page is to make an easy to use (and easy to share) central repository for my posts on the science of behavioral genetics. This is fundamental reading for anyone interested in HBD – indeed for anyone interested in the human sciences in general.

The five laws of behavioral genetics are:

1. All human behavioral traits are heritable
2. The effect of being raised in the same family is smaller than the effect of the genes.
3. A substantial portion of the variation in complex human behavioral traits is not accounted for by the effects of genes or families.
4. A typical human behavioral trait is associated with very many genetic variants, each of which accounts for a very small percentage of the behavioral variability.
5. All phenotypic relationships are to some degree genetically mediated or confounded.

This page is loaded with links to all kinds of furiously interesting things.

 

[Laura]

I found the graph below to be quite fascinating. A bit of intro to it:

A large meta-analysis of behavioral genetic studies of educational attainment (Branigan, McCallum, and Freese, 2013) performed across much of the developed world (Australia, Britain, Germany, Italy, Denmark, Finland, Norway, Sweden, Spain, and the United States) found a significant and fairly substantial shared environment component to adult educational attainment. They found that the shared environment accounted for, all told, 36% of the variance in adult educational attainment, and 24% when only people born after 1950 were considered.

Interesting, isn’t it? Very interesting, you might think. Some may be quick to declare that this invalidates all that have been saying about the non-effect of parenting. Since education is something that clearly “matters” so much in life, then parents should redouble their efforts, right?

Well, it actually turns out that it doesn’t quite work that way.

There are actually quite a few complications to this, and quite likely this doesn’t mean what it appears to mean. For one, “educational attainment” is often measured in these studies as either a quantitative variable (years of schooling completed) or a categorical one (degree attained). It doesn’t add in the obvious complication of where and how. A quick look at the previous chart of transmission of income by occupation should be one clue. Another clue is this chart by Razib Khan, that makes it abundantly clear not every bachelor’s degree is created equal:

 

[Laura]

This one is interesting:

Expectations and reality: a window into the liberal-conservative baby gap

Post edited (12/10/12). See below! Commenter szopeno once noted that if you ask women what their ideal family size is, you will get an average of about 2.1-2.5 children (trending towards the low side in Western world). As previously discussed here, the decline in fertility among Whites in...

www.unz.com

However, these data show that the liberal failure to reproduce isn’t due, by and large, to a lack of desire for children, since liberals do want typically reasonably sized families. However, the loss stems primarily from delayed marriage/family formation, particularly due to the pursuit of lengthy educations, as my earlier research showed. I’ve heard it said that women pursuing lengthy educations, assuming that can just begin to have families later in life (late 20s and 30s), fail to realize how much their fertility falls with time ...

Which will lead to this:

Genotypically, White Americans are getting more conservative, and the future will come to be dominated them (and the non-White groups in the country).