Effects of Fathers' Absence and Birth Order on Aggressive Behavior of Young Male Children

Aggression scores were obtained for 50 inner-city Hispanic males. An analysis of variance indicated a statistically significant interaction between birth order and number of parents in the household. Post hoc analysis indicated that last-born subjects reared in low-income families with fathers absent displayed more aggressive behavior than firstborn, middle-born, or last-born subjects in families with fathers present. Moreover, there was an indication that firstborn and middle-born subjects in families with fathers absent may be more aggressive than their counterparts in families with fathers present. These results suggest that birth order should be considered in studies of the behavior and personality development of males in father-absent families. Research designs should differentiate between last-born and middle-born siblings.