Critiques Rodgers et al.'s June 2000 research on the relation between birth order and intelligence, which suggests that it is a methodological illusion. Explains how the intellectual environment and the teaching function (whereby older children tutor younger ones) contribute to the growth of intellectual maturity, the first negatively and the…

Suggests that a careful review of the logical and empirical bases for the myth argument indicates that there is little to justify it. The evidence suggests that if one lives long enough, decrements in at least some of the important abilities of intelligence is likely to occur. (Author/AM)

Birth order effects on intellectual performance show both positive and negative results. Considers the intellectual aspects of siblings' changing environments, explaining that birth order and family size effects depend crucially on the age at which children are tested. Within-family data conceal patterns of aggregate effects that are revealed by…