The differential diagnosis involves consideration of the characteristics of the insane, defective, and epileptic. We repeat that we agree that the mentally abnormal person may engage in pathological lying quite apart from any expression of delusions, and that during the course of such lying the insanity may not be recognized. This occurred in many of the cases cited in the foreign literature, and if the prior histories of many individuals now in insane hospitals were known undoubtedly such lying would be frequently noted. But once the person is recognized as insane he need not be classified as a pathological liar. This term should be reserved, as we stated previously, for normal individuals who engage in pathological lying. Of course other observers have noted such lying in people who could not be designated as being mentally abnormal, but our material is peculiarly rich in examples of this kind.
CORRELATIONS STUDIED FOR CAUSES
Heredity. We come now to a very interesting group of facts—showing at once complete corroboration of previous observers' statements that pathological liars are extraordinarily ``erbliche belastet.'' Taking our 19 mentally normal cases we find the following:
Insanity in the direct family (four of these being a parent). .6
One or both parents severely alcoholic. . . . . . . . . . . . .6
Criminal or very dissolute parent . . . . . . . . . . . . . . .4
Suicide of parent . . . . . . . . . . . . . . . . . . . . . . .1
Extremely neuropathic parent. . . . . . . . . . . . . . . . . .1
Syphilitic parent . . . . . . . . . . . . . . . . . . . . . . .2
Epileptic parent. . . . . . . . . . . . . . . . . . . . . . . .1
Unsatisfactory data . . . . . . . . . . . . . . . . . . . . . .2
Reliable data showing normal family stock . . . . . . . . . . .2
Thus, out of the 19 cases there are only three or four which do not come of stock showing striking defects. Now, as we go on to show later that unfortunate conditions or experiences were often causal factors, the total findings seem to show clearly that these latter influences generally bore their unfortunate fruition upon inherited instability.
The heredity in the border-line cases is, as might be expected, even worse. These facts are easily discerned in their respective case histories.
The question of inheritance of similar mental traits is, of course, important. We have found absolutely no proof of the trait of pathological lying, as such, being inherited. The reader will note with interest particularly the facts in Cases 2 and 4, where we at first thought we had to deal with inheritance, but later found there was no blood relationship between the supposed parent and child. In those instances the lying of the younger individual was much more likely to be the result of psychic contagion, and this also may be largely the explanation of Cases 6 and 8, where an older relative was well known to be a prevaricator. The bad inheritance in these cases then turns out to be, corroborating what we found in studying the general problem of criminality,[25] a matter of coming from stock that shows defects in various ways-all making, however, in the offspring for moral instability.
[25]``Inheritance as a Factor in Criminality. A Study of a Thousand Cases of Young Repeated Offenders.'' Edith R. Spaulding and William Healy. pp. 24. Bulletin of the American Academy of Medicine, Vol. XV. February 1914.
Developmental Physical Conditions. Inquiry into our 19 mentally normal cases gave the following findings: Antenatal conditions were defective in 2 cases on account of syphilis and in one case from advanced age of the mother. The accident during pregnancy to the mother in one case, the severe mental shock in another, and the effect of illegitimacy in still another we can not evaluate. In 2 cases there were operative births with, however, no bad results known. One was a twin. Early severe disease of the nervous system was experienced by one, and convulsions during infancy by two others. Another suffered from some unknown very severe early illness, and one from prolonged digestive disturbance in infancy. Three had in early childhood several severe illnesses, one had a long attack of ``chorea.'' Two suffered from general nervousness, incited in one case by the excessive use of tea and in the other by a similar use of coffee. One was an habitual masturbator from childhood. Difficult menstruation was reported in only one case. In 5 cases there was a quite normal early developmental period, according to reliable accounts. In 3 cases the early developmental histories are completely unknown, and in 3 others uncertain. The data of developmental history in the border-line types may be easily noted in the case histories.
Previous Ailments. Ailments suffered from in our 19 cases after the early developmental period amount to very little. The several gynecological troubles have been mentioned above under the head of Physical Conditions. In one other case there had been urethritis previously. Head injuries, which play such a significant part in the study of criminalistics, find no place in our mentally normal series, but should always be kept in mind in considering the border-line types. Epilepsy as a possible factor in criminalistic problem cases is to be remembered.