Birth Order and Personality Traits of Students: A Study Using NEO PI-R

irth order is a personality concept that was first introduced by Alfred Adler in 1908. Adler and Adlerian psychologists believe that birth order has an important impact on lifestyle development. Birth order has inspired more researches than other concepts of Adler's theory. Some of these researches support Adler's idea about the impact of birth order on personality structure while others report that birth order has little or even no impact on personality. The contradiction in the results has frequently caused so many researches by different researchers in various societies. Iranian researchers have conducted a number of researches none of which, however, address the relationship between personality and birth order. The main aim of this research is to prove the impact of growing environment and birth order on personality. It is a descriptive research using causal-comparative method to compare the impact of three birth orders (first, middle, and last) on personality. The important question addressed was whether students with varied birth orders were different in the five indexes and thirty scales of NEO inventory. Sample group was 75 students of Tehran-based universities who replied to the Revised NEO Personality Inventory (NEO PI-R). Analysis of findings by MANOVA showed that there was a significant difference in the mean of the three birth orders in three indexes of NEO inventory; openness, agreeableness and conscionable as well as its fifteen scales; aggression, depression, self-consciousness, gregariousness, excitement, fantasy, aesthetics, actions, feeling, ideas, trust, straightforwardness, dutifulness, achievement striving and self-discipline. This result is consonant with Adler’s theory and those researches that support the impact of birth order on personality structure.