Do you have higher birthweight than your twin?
A new study of twins by researchers at Georgetown University, looked at the effect of birthweight on children's cognitive and socioemotional outcomes at 4 years old, taking into account families' socioeconomic status (SES). The study showed that weighing more than your twin before starting school may help with achievement.
"Our study suggests that higher birthweight predicts greater school readiness, more so for low-SES children," notes Caitlin Hines, a doctoral student at Georgetown University, who led the study. "It follows that early intervention with lower-birthweight infants may reduce the long-term implications of birthweight. Such intervention should address cognitive or socioemotional deficits before kindergarten."
Researchers used data from the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B) to compare the outcomes of 1,400 twins whose birthweight differed from one another.
The authors explain that the study found that higher birthweight significantly predicted higher math and reading scores at age 4. Higher birthweight also significantly predicted decreases in externalizing behavior (behavior that is aggressive, impulsive, or disruptive) and increases in prosocial behavior (behavior that is friendly, empathetic, or interested). These estimates suggest that weighing more than your twin is associated with small decreases in externalizing behavior and small increases in prosocial behavior prior to school entry.
The authors point out several limitations to their work. Because twins tend to weigh less at birth, are born earlier, and have more birth complications than singletons, the study's results may not apply children who are not born as twins. In addition, only children who attended nonparental care had provider-reported behavior scores, and children in parental care tend to be more disadvantaged than those in nonparental care, which may underestimate the effect of birthweight on provider-reported behavior.
(Content Courtesy: Society for Research in Child Development