Final answer:
Erik Erikson focused on the role of childhood in personality development and proposed the Psychosocial Theory of Development, indicating that personality continues to evolve across the lifespan. Alfred Adler also contributed ideas about how birth order affects personality.
Step-by-step explanation:
The psychologist who believed that childhood was a significant time for personality development and emphasized social conflicts and individual psychology, including the role of birth order, was Erik Erikson. Unlike Freud, who proposed that personality development occurs only in childhood, Erikson developed the Psychosocial Theory of Development, suggesting that personality development continues throughout an individual's lifespan. Additionally, another key figure is Alfred Adler, who contributed to the idea that birth order significantly influences personality, a concept that considered the social and familial dynamics affecting development.