3. Unfortunately for social reform, a wholly incorrect impression seems to have spread abroad that half of the delinquents in _juvenile courts_ are feeble-minded. Exaggeration of the condition retards rather than assists a sane public policy regarding the indefinite isolation of those demonstrably deficient by psychological tests. The mistaken impression apparently started with the study of Goddard and Gifford as to the condition found among boys at the Newark Detention Home. Two-thirds of these boys tested approximately below our borderline for clearly passable intellects. I should not be inclined seriously to question calling these two-thirds in the Newark Home feeble-minded, since I am willing to class those in our doubtful group as feeble-minded provided that they are persistent delinquents. The deductions which were drawn from this startling discovery seem, however, to have slipped into the literature of the subject without anybody noting that they were unjustified by the facts. In the first place the condition at Newark Detention Home may reflect a peculiar local situation analogous to that at Pittsburgh in which deficient boys had to be cared for in the detention home because no other institution was available for these feeble-minded. Under these recognized local conditions, it would seem that the general situation might be better represented by the conditions of deficiency found since then in Cook and Hennepin counties than by the conditions at Newark. We at least know that Newark and Pittsburgh represent special and not ordinary conditions among those in local detention homes, unless the situation is very different in the East from that in the West. Besides regarding the condition in the Newark Detention Home as representative of the general condition in detention homes elsewhere, it was argued that the condition in the detention home represented the condition among the ordinary cases of delinquents before the juvenile courts. The groups in detention homes are undoubtedly extreme both as to the seriousness of their delinquency and as to their deficiency. Since Goddard published his paper following the Newark study considerable additional evidence has been made available. But even without this contradictory data, it was a big jump to assume that the condition in the local detention home represented the frequency of deficiency among the ordinary cases which come before the juvenile courts.