Another review of Dysgenics was written in 2002 by Nicholas Mackintosh , emeritus professor of experimental psychology in the University of Cambridge.  Mackintosh wrote that, "with a cavalier disregard for political correctness, he argues that the ideas of the eugenecists were correct and that we ignore them at our peril." While recognising that the book provides a valuable and accurate source of information, he criticised Lynn for "not fully acknowledg[ing] the negative relationship between social class and education on the one hand, and infant mortality and life expectancy on the other." He questioned Lynn's interpretation of data. He also points out that according to Lynn's reading of the theory of natural selection, "if it is true that those with lower IQ and less education are producing more offspring, then they are fitter than those of higher IQ and more education". According to Mackintosh, eugenicist arguments are not based on a "biological imperative, but rather on a particular set of value judgements."
8 Now, how can we account for these facts on any of the known data on which we have at present to rely ? In my opinion, we shall have to go far deeper down than we have been able to go by any present means of observation--to the corpuscles, atoms, electrons, or whatever else there may be; and we shall find these subjected to subtle influences of mind and body during their formations and combinations, of which we hardly realize the importance. I believe that in these potent factors the solution of the problem may be found why one member of a family rises above others, and others do not rise above the ordinary level, but perhaps sink below it. To me it seems, when I consider this matter in regard to these difficulties, that in making a comparison with the improvement of breeding of animal stock we may be apt to be misled. We are all organic machines, so to speak; at the same time, when we come to the human being there are complexities which arise from the mental state and its moods and passions which entirely disturb our conclusions, which we should be able to form in regard to the comparatively simple machines which animals are.