Thirteen doctoral dissertations and five masters theses are summarized in this report of research on the disadvantaged child. Contained in each individual summary are the detailed descriptions of the experimental task, the results obtained and the analysis of these results. The eighteen individual theses are concerned with topics such as: cognitive functioning; language; attention; intelligence; affective functioning; socio-affective development; motivation and self-concept; attitudes towards school; and programs of intervention. The report concludes with a brief analysis of the principal contributions of all of these works. (BV)