This doesn't make any sense. He's taking a study over 20 years old designed to measure academic consensus and then using it to try and disprove 29 textbooks aut

This doesn't make any sense. He's taking a study over 20 years old designed to measure academic consensus and then using it to try and disprove 29 textbooks authored by leading psychologists. Couldn't the latter be said to be a (much more recent) form of academic consensus? Why should a measure of academic consensus over 20 years old be used as some kind of evidence against newer ideas?