Birth Order and Intellectual Performance in East Africa

The generalizability of birth order effects found by Zajonc and Markus was investigated for a sample of 1400 high school students in rural, sub-Saharan Africa. For three intellectual test scores, performance declined as a function of birth order. Variations from monotonicity included a reversal of the performance of ranks I and 2, markedly superior performance of birth ranks 1-3 over lower ranks, and very poor scores for those at ranks 7 and lower. Family size was unrelated to test score performance. The variations were tentatively attributed to sociocultural factors that may have affected the quality of the intellectual environment for this sample.