Personality traits that may be affected by birth order include a person's social skills, sense of importance, competitiveness and goal preferences, notes Psychology Today. Studies show that the perceived effects of birth order on personality form primarily from parental behavior rather than strictly order of birth.
Personality traits typically attributed to a certain position in birth order also tend to appear in atypical family situations, such as when a significant age gap exists between first- and second-born children. In such situations, the second-born child often develops traits usually attributed to first-born children, notes Psychology Today. Some of the distinct personality traits of firstborn children are due to the fact that first-time parents experiment more with rearing techniques and typically provide more attention to their child, writes Parents Magazine.