The aim of this study is to investigate the effects of birth order on conscientiousness, openness and self-esteem between participants of 18-60 years of age. The sample consisted of 206 participants (male = 30, female = 176) who fell into one of the five category’s, firstborn, middle-born, last-born, only child and other. Participants completed an online survey which comprised of two different questionnaires, Rosenberg’s Self-Esteem Scale and a subscale of the Big Five Inventory. An ANOVA was used to examine the results and were compared to verify any significant differences between birth order and each of the different variables. The results revealed that there was no significant difference existing between birth order and the psychological variables examined.
Author Keywords: birth order, personality, conscientiousness, openness,