Summary
Ss were 158 male and 160 female university students. The Holmes-Tyler self-peer rating and Mehrabiah resultant measures of achievement motivation showed no significant relationships to ordinal position, family size and density, or sex/ordinal position dyads. Family size, as well as a family size and density index, showed significant interaction with father's occupational status in three out of eight analyses of variance involving occupational status. Some characteristics of the family size and density index were discussed.