Personality is influenced by many factors including family, environment, and genes. Birth order may also impact personality development - firstborns tend to be overachievers, leaders, and organized while middle children are often easygoing, social and peacemakers. Last borns are more likely to be risk-taking, creative, and fun-loving compared to firstborns who are often cautious and responsible and middle children who are people-pleasers. Only children tend to be hardworking but also self-centered and perfectionist due to lack of siblings.