Tag Archives: heritability

Different kinds of nature-nurture science

The different ways that researchers and others invoke hereditary versus environmental influences are often subsumed under the label nature versus nurture. Let me, in contrast, distinguish several disjunct areas of nature-nurture science:
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What has Nature vs. Nurture got to do with Nature vs. Nurture? III

previous post considered the connection between two different Nature-Nurture issues: the matter of fixity versus flexibility in the development of traits in individuals over their life course and the relative degrees of hereditary versus environmental influences on the variation of the trait between versus within groups? (“Groups” here refers to males or females, but the question might be extended to socially defined racial or socio-economic groups.)  Continue reading

What has Nature vs. Nurture got to do with Nature vs. Nurture? II

The previous post asked about the connection between two different Nature-Nurture issues: the matter of fixity versus flexibility in the development of traits in individuals over their life course and the relative degrees of hereditary versus environmental influences on the variation of the trait between versus within groups? (“Groups” here refers to males or females, but the question might be extended to socially defined racial or socio-economic groups.)  Continue reading

What has Nature vs. Nurture got to do with Nature vs. Nurture?

How difficult is it to change the typical distributions of a trait, such as aggression, substance abuse, suicide attempts, as the distributions differ between males and females? Nature versus Nurture debates build off this question in two ways. One is the matter of fixity versus flexibility in the development of traits in individuals over their life course. The other is the relative degrees of hereditary versus environmental influences on the variation of the trait between versus within groups. (“Groups” here refers to males or females, but the question might be extended to socially defined racial or socio-economic groups.) What have these two Nature-Nurture issues got to do with each other? Continue reading

50 whys to look for genes: 35. Find “missing heritability”

[G]enomic studies have had difficulty identifying causally relevant genetic variants behind variation in human traits (McCarthy et al. 2008, Couzin-Frankel 2010). Even when many genetic variants are examined together, only a small fraction of the variation in the trait is associated with—or in statistical terms, “accounted for” by—the genetic variants. This finding has led to discussions about missing heritability (e.g., Manolio et al. 2009)…

and bridging the gap by finding additional genetic variants (e.g., Wheeler and Barroso 2012). Continue reading

50 whys to look for genes: 33. Advice to relatives

As noted in an earlier post, high heritability might mean that the similarity between twins or a set of close relatives is associated with the similarity of yet-to-be-identified genetic factors [but] the factors may not be the same from one set of relatives to the next, or from one environment to the next.  This is one reason why translation from estimation of heritability to hypotheses about measurable factors is difficult.  One response to this situation is Continue reading

50 whys to look for genes: 28. Genetically-informed social science

Turkheimer, Emery, and their students have analyzed the similarity of offspring of monozygotic twins with the aim of clarifying the relationship between parental traits, especially divorce, and the behavior of their offspring. Turkheimer (2008, 4) describes the logic of their analyses in two scenarios:

[I]f a genetic propensity to be aggressive makes parents more likely to get divorced, and those same genes when passed to the children make them more likely to be aggressive on the playground, then one will observe an association between divorce and playground aggressiveness that will not really be a causal consequence of divorce….But in identical twin parents…none of the differences between the children can arise from differences in the genes of their twin parent, so if the children do differ, we can (almost…) rule out a genetic explanation of the association.

Conversely, Continue reading