Julian Bajczyk

Date Approved


Embargo Period


Document Type


Degree Name

M.A. School Psychology-Professional School Psychology




College of Science & Mathematics


Dihoff, Roberta

Committee Member 1

Klanderman, John


Birth order; Risk-taking (Psychology); Teenagers


Child Psychology | Student Counseling and Personnel Services


This study is based on research performed in 2006 by Laura Argys, Daniel Rees, Susan Averett, and Benjama Witoonchart. The 2006 study investigated relationship between the birth order and an adolescent's likelihood of engaging in certain risky behaviors. For the purpose of this study these behaviors include things like drug use, sexual activity and violent or antisocial offenses. The initial study found a trend implicating that adolescents with older siblings more likely to engage in certain risky behaviors than adolescents who did not have older siblings (eldest and only children). The Argys, et al. study used data collected from the first round of the National Longitudinal Survey of Youth (NLSY) '97, using responses from 9,000 participants aged 12-17 years. The present study seeks to determine if this trend persists in the population as the participants age. Data was taken from the year 2000 of the NLSY'97 when the participants are 15-20 years of age. Responses were collected from 8,150 participants. An independent samples t-test was used to compare the average rates of engagement among boys and girls with and without older siblings between the two years. A chi squared test for independence was performed to identify the relatedness of the two samples.