The Effect of Height on Adolescents' Body Image Perceptions and Behaviors

This paper estimates the causal effect of height on adolescents’ body image, encompassing self-perceptions of weight, the accuracy of those perceptions, and weight-management aspirations. Using data from the National Longitudinal Survey of Youth 1997 (NLSY97), we leverage within-individual variation in height during adolescence and condition on body mass index (BMI) to isolate the effects of height on body image outcomes. We find that taller adolescents are more likely to perceive themselves as overweight, even holding BMI constant, and are less likely to underestimate their weight category. However, the direction of misclassification diverges by gender: taller boys are more likely to correctly assess their weight category, while taller girls are more likely to overestimate it. These perception shifts translate into behavioral responses for girls but not for boys. A one-inch increase in height raises the probability that a girl reports wanting to lose weight by 3.0 percentage points (6.2 percent), with effects concentrated among girls in the normal weight range. Taken together, these findings establish height as a salient determinant of body image in adolescence, operating independently of body mass.