That link is behind a paywall. Can you give a tl;dr of how this book has been debunked? Or more specifically how it doesn’t put the question of IQ difference between racial groups into perspective.

As far as I’m aware this book was released in the 80s over a decade before The Bell Curve was released, the latter cited research dated after the release of the former, which Mismeasure was very much concerned with. Are you maybe thinking about the brain weight research that Mismeasure is talking about in the early chapters? If so, those were there only to provide a historical perspective. I can assume most readers already knew those research were well outdated before publication (and Gould even says so in the book).