Lehman, H. C., & Witty, P. A. (1926). The negro child's index of more social participation. Journal of Applied Psychology, 10(4), 462-469.
http://dx.doi.org/10.1037/h0073684
On the basis of data obtained by the administration of the Lehman Play Quiz the authors compare two groups of negro children with two groups of white children with respect to their participation in social or solitary play activities. The per cent of the total activities that the social activities represent is designated the index of social participation. The tables of data indicate that at every age interval (8½ to 15½) negro children are more social in their play than white children. It is suggested that the negro child's greater sociability may be a handicap rather than an asset as far as a well-balanced development is concerned. (PsycINFO Database Record (c) 2016 APA, all rights reserved)