Using our conservative basis for interpreting the results of Binet examinations, let us now review the evidence of the proportion of delinquents which is intellectually deficient. We shall compare the available data on groups of tested delinquents which have not been subjectively selected, provided that the data permit of restatement on the basis of the borderlines we have adopted. The evidence of tested deficiency on over 9000 objectively selected delinquents has thus been assembled under approximately the same interpretation of the borderlines. This should help to make it clear how extensive the preparations must be for dealing with this problem of the defective delinquent and where the needs are most pressing. It should also enable us to discover when the estimates have been excessive. We shall confine ourselves to the reports of objective test examinations, so that the estimates do not depend upon the judgment of the examiner alone. A bibliography of these studies is given at the close of the book. How much more has been accomplished in this field in the United States than abroad is illustrated by the fact that repeated search has failed to discover any reports of Binet examinations on representative, randomly selected groups of delinquents in any foreign country. Binet examinations have been made of juvenile delinquents in Breslau (_34_) and in Frankfurt a. M., and in London (_56_); but only upon selected cases. Those who wish to compare the results as to tested deficiency with the subjective opinions of various estimators should consult the reviews of this literature by Bronner (_6_) and by Gruhle (_121_). The effect of such a comparison is an increasing conviction that it affords dubious evidence of the relative amount of deficiency in different groups of delinquents. Without objective tests, there is no means of telling what amount of mental retardation the different experts would class as feeble-mindedness. (a) WOMEN AND GIRL DELINQUENTS IN STATE INSTITUTIONS. Women in state penitentiaries are a small group among delinquents in institutions. According to one study by Louise E. Ordahl and George Ordahl[15] the frequency of tested deficiency is smaller among them than among women committed to reformatories, who in general commit less serious crimes. All except one of the 50 women prisoners enrolled were tested with the Kuhlmann 1911 revision of the Binet scale. About half were negro women. Only 6 (4 negroes) tested IX or below and were in our group of presumably deficient by the tests. Twenty others (13 negroes) tested one Binet age higher and were in the doubtful group.