Birth order effects in dominance: failure to support Sulloway's view

Contrary to Sulloway's 1996 assertion that firstborns should score higher than laterborns on measures of dominance, the dominance scores for 76 firstborn undergraduate students (50 women, 26 men) did not differ significantly from the scores of 75 laterborn students (48 women, 27 men) on the 16PF dimension of Dominance vs Submissiveness (Factor E). Further research into possible differences in performance strategies between laterborns and firstborns in childhood vs adulthood is necessary to evaluate Sulloway's theory of ordinal position definitively.