According to Erikson,humans are fully developed by the time they reach adulthood.

Erikson's theory of psychosocial development includes eight stages that continue throughout the lifespan, with each stage presenting a unique developmental task or crisis. The final stage, which occurs in adulthood, is called "Integrity vs. Despair" and involves reflecting on one's life and accomplishments. While Erikson believed that individuals could continue to develop and grow throughout their lifespan, he did not suggest that humans are fully developed by the time they reach adulthood.