Binet's suggestion as to the diagnosis of mental development seems to be best. He says that “the selection of defectives calls for three varieties of experience—that of teachers, of doctors, and of psychologists” (_77_, p. 38). These three points of view may be combined in a committee as in France, or the decision may rest with a specialist in mental development whose judgment should only be given after he has all the information which the medical, educational, and social diagnosis can provide to supplement his test records and his evaluation of the causes of the condition found. Those who are considering the legal isolation of the feeble-minded, especially defective delinquents, and superintendents who wish a safe rule for transferring school children to special classes or schools for the mentally retarded should keep a committee plan in mind. A legal requirement embodying an examination by such a commission could easily be framed. In my opinion the expert in mental development should be required at least to have the equivalent of a year of graduate work with his major time in testing. On the other hand very desirable information as to children that require examination may be obtained by a teacher who uses a mental scale intelligently. In the hands of an amateur it may perform an analogous service to that of a vision chart in discovering children who require expert examination of their eyes. The danger lies in the novice not knowing his limitations. Few who have had experience with tests can doubt, however, the much greater danger of inadequate diagnosis of mental development on the part of physicians who give opinions about mental deficiency without having had experience with test scales. ----- Footnote 30: Italics mine. CHAPTER VIII. SCHOOL RETARDATION AMONG DELINQUENTS A. IN MINNEAPOLIS Besides the estimates of deficiency based on tests, the school records may furnish valuable objective evidence about mental retardation among delinquents. The school environment is the first prominent social environment to which the child must adjust himself. If he fails in this while in regular attendance we have an important indication of mental deficiency. With laws which require attendance at school, we may even estimate the mental character of groups, on the basis of success in school, provided that we use proper caution as to the effects of late entrance and of absence from school. Moreover, whether retardation in school shows mental deficiency or not, it certainly sets forth a vital problem in connection with delinquency. We shall first consider the school retardation of delinquents and leave the problem of checking the tests by school records until later.