In Chapter 4, Gould presents two additional 19th-century theories of measurable intelligence inspired by evolutionary theory: recapitulation (the reconstruction of genetic lineages) and criminal anthropology.

Recapitulation, a theory originated by the zoologist Ernst Haeckel (1834-1919), was also used to illustrate the stages of human psychological or educational development. For scientists interested in ranking human groups, recapitulation was seen as a “general theory of biological determinism” wherein the “adults of inferior groups must be like children of superior groups” (144). In this framework, adult blacks and women who behaved like white male children were proof of the evolution of white males. Scientists from wide-ranging fields developed numerous theories outlining a lineage of white superiority, including E.D. Cope (paleontology), D.G. Brinton (anthropology), G. Stanley Hall and James Sully (psychology), and Herbert Spencer (evolutionary biology).

Theories of recapitulation ceased with the onset of Louis Bolk’s theory of neoteny, which proposed an opposing idea that the “juvenile traits of ancestors develop so slowly in descendants that they become adult features” (148). Although this theory contradicts the essential principal of recapitulation, like the recapitulationists, Bolk and other scientists of the period used neoteny to justify their arguments for the superiority of whites and inferiority of blacks.

Gould then introduces the last theory of body measurement, Cesare Lombroso’s theory of the criminal man, which is based on “a specific evolutionary theory based upon anthropometric data” (153).