Submitted by **Chance_Literature193** t3_11i764u
in **askscience**

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**SerialStateLineXer**
t1_jb0xois wrote

Reply to comment by **GeriatricHydralisk** in **Understanding Heritability (h^2) Statistic?** by **Chance_Literature193**

>So to estimate heritability, you regress your height against the average of your parents' heights.

No, you can't estimate heritability that way, because this can't distinguish between genetic and environmental transmission of traits.

Traditionally, heritability is estimated with twin studies, using Falconer's formula. You compare the correlation between pairs of monozygotic twins to the correlation between pairs of same-sex dizygotic twins. You can exploit the fact that MZ twins are twice as genetically similar as DZ twins but MZ and DZ twins are raised in equally similar environments to determine heritability.

So if the MZ correlation is 0.7 and the DZ correlation is 0.4, this implies that 60% (2 * (0.7 - 0.4)) of the variation in the trait can be attributed to genetics, 30% (1.0 - 0.7) to non-shared environment (environmental factors that differ between twins) and the remaining 10% to shared environment (environmental factors that are the same for both twins).

There are some additional adjustments you can do for things like gene-environment correlation, but that's the simplified version.

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**[deleted]**
t1_jb1f1za wrote

[removed]

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**Georgie___Best**
t1_jb4u7v7 wrote

>No, you can't estimate heritability that way, because this can't distinguish between genetic and environmental transmission of traits.

What do you mean by environmental transmission of traits?

Parent-offspring regression is definitely one way to estimate heritability. It has flaws and biases, but no more than estimates derived from twin-studies, which tend to overestimate narrow-sense heritability.

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**SerialStateLineXer**
t1_jb5l8n8 wrote

Are you under the impression that heritability of height is defined as the correlation between children's heights and the average of their parents' heights? Obviously you can determine that by calculating said correlation, but that's not what heritability means.

Heritability refers specifically to share of variation in a trait attributable to genetic variation. I suppose it's possible that there's some field other than genetics in which the term is used to refer to the degree to which children are similar to their parents, but the original question specifically referred to the definition used in genetics, and you definitely can't calculate that by comparing children to their parents. If you could, twin studies would never have been invented. That's the exact problem they were invented to solve.

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**Georgie___Best**
t1_jb65yb6 wrote

Somewhat surprised that you're familiar with the concept of heritability, but not yet come across regression of offspring on mid-parents as a method to estimate it. For example:

Parent-offspring regression to estimate the heritability of an HIV-1 trait in a realistic setup

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