THE PRESENT REPORT deals primarily with studies appearing since the publication of two summaries by Jones (66) and Shock (120) in 1939. The topics covered include mental development as related to (a) structural characteristics represented in measurements of height or other body dimensions, or in assessments of skeletal maturity; (b) physical or sensory handicaps; (c) factors associated with premature birth, birth month, age of mother, birth order, etc.; (d) physiological factors such as are involved in nutrition, endocrine functions, drug effects, etc.; and (e) disease conditions, such as encephalitis, poliomyelitis, allergies, tuberculosis.
Mental Development and Structural CharacteristicsHeight and weight-As previously noted (66), it is usually found that a low positive correlation, rarely higher than .30, exists between the intelligence of children and their physical development as expressed in height or weight. In line with this, Middleton and Moffett (86) reported a correlation of .22 between intelligence and height and .15 between intelligence and weight in a group of 490 college freshmen. No significant relationship was found between physical measurements and scores on the Bernreuter test (85). Somewhat surprising are the results obtained by Katz (67) for 112 boys and 117 girls who received Stanford-Binet tests semiannually between the ages of three and five years. Contrary to the usual experience, no significant correlations were obtained for the boys between median IQ and height or weight. For the girls, on the other hand, exceptionally high correlations were obtained: IQ with height, .40; with weight, .34. It is probable that these findings are the result of special conditions in the selection of samples. An "unexpectedly high relation between intelligence quotient and stature" has been announced by Boas in a recent study (18), but his report gave neither the magnitude of the correlation nor other data necessary to appraise the conclusions reached.Weight at birth-Particularly in connection with studies of premature children the question has been raised as to whether weight at birth would show a relationship to subsequent intelligence. No relation has been found in American studies by Hess, Mohr, and Bartelme (62) or by Benton (11). Brander (24), however, in an investigation of Finnish
