[l0t0b0r0s]

>some of heritability is genetics and some is the shared environment.

This is not the definition of heritability you are mincing words.

Heres the definition of heritability:

(HAYR-ih-tuh-BIH-lih-tee) The proportion of variation in a population trait that can be attributed to inherited GENETIC factors.

>For example, someone is quite likely to speak the same first language as their parents, and for this reason, the statistics for heritability come up with a high number for how heritable a trait first language is.

you are conflating inheritability with heritability.

The reason we are able to have crops that yield more is because we genetically modified them to do so; not because we grew wild corn in the perfect environment.

[tptacek]

You're lost here. Heritability is defined technically as h^2 = V_a / V_p, with V_a additive genetic variance and V_p phenotypical variance. Look at your hands. The number of fingers on it are extremely genetically determined; the Hox genes that define your body plan are very conserved. V_a is practically zero. But plenty of people have fewer than 5 fingers, and some are born that way (for instance, children exposed in utero to Thalidomide); V_p is nonzero. Evaluate the expression (0/nonzero).

If you read your own words carefully, you're trying to rebut the parent commenter with their own argument.