Editing The Bell Curve (section)

==== Criticism by Ned Block ====
{{See also|Race and intelligence#heritability within and between groups}}
Philosopher [[Ned Block]] argues that ''The Bell Curve'' misleads about intelligence as it conflates genetic determination with [[heritability]].<ref name=":2">{{Cite web |last=Block |first=Ned |date=January 6, 1996 |title=How Heritability Misleads about Race |url=https://www.nyu.edu/gsas/dept/philo/faculty/block/papers/Heritability.html |website=[[NYU]]}}</ref> Genetic determination and heritability are not interchangeable as there are traits that are genetically determined but not heritable, and vice versa. For example, the number of fingers on a human hand is genetically determined as genes code for five fingers in nearly everybody. However, the heritability of the number of fingers is very low, as variations in numbers of fingers are usually environmentally caused. The aforementioned earring example quoted by Chomsky is an instance where the opposite is true: high heritability, but not genetic determination.<ref name=":2" /> Given that genetic determination and heritability are not equivalent, Block contends that IQ is one such trait that is heritable but not genetically determined. Finally, Block contends that using twin studies to randomize the environment automatically fails: Black twins will always bring a part of their environment with them as they are both Black and will be treated as such.<ref name=":2" />

Canadian psychologist [[Sidney Segalowitz]] concurs with Block that twin studies fail to draw conclusions about heritability, and as a result Murray's work is methodologically flawed.<ref>{{Cite journal |last=Segalowitz |first=Sidney J. |date=October 1999 |title=Why twin studies really don't tell us much about human heritability |url=http://dx.doi.org/10.1017/s0140525x99442207 |journal=Behavioral and Brain Sciences |volume=22 |issue=5 |pages=904–905 |doi=10.1017/s0140525x99442207 |s2cid=143865688 |issn=0140-525X}}</ref>