vi THE ANATOMY OF HUMAN PERSONALITY 259
differences to be inborn. He states that they can be modified, as when a natural-born introvert is forced by circumstances into extraversion, but believes that such transformations are superficial and that an abrupt change is likely to result in a psychoneurotic condition.
From time immemorial a tradition has existed that persons of a certain body type, build, or habitus, show characteristic traits of personality. Thus Shakespeare puts into the mouth of Julius Caesar :
' Let me have men about me that are fat : Sleek-headed men and such as sleep o' nights : Yond Cassius has a lean and hungry look ; He thinks too much : such men are dangerous.'
This tradition asserts that the rotund body type indicates the good mixer, the diplomat and the leader. Thin men are alleged to be moody, introspective and given to solitude.
A recent version of the doctrine of body types is that/ of Kretschmer.134 This German psychiatrist distinguishes two principal types of habitus, with some intermediate and combined classes. The Pyknic type is described as characterized by full faces, short necks, rounded limbs and a tendency toward stoutness. The asthenic type is the opposite, with an angular profile, a slender but often wiry body, and with outstanding muscles or bones. The principal intermediate type is termed the athletic, which may briefly be described as neither too stout nor too thin. Kretschmer classified 260 mentally deranged patients according to these types, making his classification on the basis of observation rather than by exact anthropometric measurement. He seemed to find that the dementia praecox (autistic personality) patients were overwhelmingly of the asthenic type, while the manic-depressives (cyclic personality)