They make some pretty specific claims though, it's not like it's "one researcher" vs "29 textbooks". Textbooks can be written poorly too, you know. For example:

They make some pretty specific claims though, it's not like it's "one researcher" vs "29 textbooks". Textbooks can be written poorly too, you know. For example: > In contrast, fewer than a quarter of the books covered the most strongly supported contemporary, hierarchical theories, such as Carroll’s three-statrum model and CHC theory each of which posits the influence of a general intelligence on other cognitive abilities. > The most common inaccuracy (appearing in nearly half the books) was that intelligence tests are biased against particular groups or individuals. This contradicts the 1997 consensus statement which tackles this issue and concludes that “intelligence tests are not culturally biased”.