Birth order is a commonly discussed topic in the field of psychological research. Many studies have been organized to show the differentiation of personality according to birth order. Personality characteristics, unrelated to birth order, play a monumental role in how a person responds to social influence. A main examination will take place regarding the opinion of the firstborn compared to the later born child with the aim of illustrating how their susceptibilities differ from each other. A related but separate analysis will be carried out encompassing the personality characteristics of the firstborn, as well as the later born individual, focusing on the big five dimensions of personality. An observation about an individual's personality characteristics suggests causality in why they behave the way they do. Studies have shown that firstborns are more extroverted, conscientious, and neurotic than later-born individuals (Herrera & Zajonc, 2003). Firstborns tend to be more extroverted (Sulloway, 1999) and are more likely to lead and dominate their younger children (Sulloway, 1999). The first-born group was also more conscientious than the later-born siblings. The pool is often more academically successful, organized, responsible and determined (Sulloway, 1999). The head of the gene pool in current generations will sometimes seek parental approval by acting as a “substitute” parent to younger siblings (Sulloway, 1999). They tend to identify with their parents, be conscientious and respectful of authority (Sulloway, 1999). Finally, the group turns out to be more neurotic than the later-born individual, in the sense of being capricious and...... middle of article ......g and Clinical Psychology, 36(2) , 171 -176. doi:10.1037/h0030717McGurk, H. and Lewis, M. (1972). Birth order: A phenomenon in search of an explanation. Developmental Psychology, 7(3), 366. doi:10.1037/h0020037Sampson, EE (1962). Birth order, fulfillment of needs and compliance. Journal of Abnormal and Social Psychology, 64(2), 155-159. doi:10.1037/h0045120Schachter, S. (1964). Birth order and sociometric choice. Journal of Abnormal and Social Psychology, 68(4), 453-456. doi:10.1037/h0044836Staples, FR and Walters, RH (1961). Anxiety, birth order, and susceptibility to social influence. Journal of Abnormal and Social Psychology, 62(3), 716-719. doi:10.1037/h0048183Sulloway, F.J. (1999). Order of birth. In Encyclopedia of Creativity, 1, 189-202.Warren, J.R. (1966). Birth order and social behavior. Psychological Bulletin, 65(1), 38-49. do I: 10.1037/h0022739