Summary Previous research with United States samples suggests that birth order findings in the area of interpersonal behavior can best be conceptualized in terms of the firstborn S's stronger need to make social comparisons. The model of Ring et al. hypothesizes that the salience of social comparisons for firstborns suggests they will differ from later-borns on variables such as need for social approval and empathy. Partial support for this model's implications was found in a study of the personality correlates of birth order among 804 Panamanian adolescents. Firstborn females exceeded later-born females in both need of approval (p < .05) and, marginally, in empathy (p < .10). Firstborn males evidenced less empathy (p < .02) than did later-born males.