The first family generation was born in the late 18th century. The third generation, the focus of the study, included Sam who was arrested for shooting to kill and for incest with his daughters, and Pearl. Sam's brother had a history of alcoholism, incest, rape, shooting to kill, and willful destruction of property, while his sisters were prostitutes. Similar to other proponents of defective delinquency theory who base their beliefs on the concept that the feeble-minded are inherently criminalistic and that most criminals are feeble-minded, the author regards the intellect as a kind of harness on the instincts. The feeble-minded such as Sam, cannot control their basic impulses; they must be held in institutions that provide the restraints they lack. 7 figures.