It’s something I’ve head over and over again but that is corrected in this preprint by Cesario, Johnsson & Eisthen from which this is the abstract:

A widespread misconception in much of psychology holds that (1) as vertebrate animals evolved, “newer” brain structures were added over existing “older” brain structures and (2) these newer, more complex structures endowed animals with newer and more complex psychological functions, behavioral flexibility, and language. This belief, though widely shared in our introductory textbooks, has long been discredited among neurobiologists and stands in contrast to the clear and unanimous agreement on these issues among those studying nervous system evolution. We bring psychologists up to date on this issue by describing the more accurate model of neural evolution, and we provide examples of how this inaccurate view may have impeded progress in psychology. We urge psychologists to abandon this mistaken view of human brains.