Final answer:
It is false that personality structure is set by age 30; personality continues to grow throughout the lifespan, influenced by both genetic and environmental factors.
Step-by-step explanation:
It is false that psychologists today believe that the basic structure of personality is in place by the age of 30. Theories of personality development, such as Erik Erikson's psychosocial theory, suggest that personality continues to develop and evolve throughout an individual's lifespan, influenced by changes, experiences, and social interactions.
While genetic factors and temperament play a significant biological role in shaping personality from an early age, environmental factors, including the culture and society one is raised, also significantly impact personality. Furthermore, the Big Five personality factors show some changes across one's life, indicating that personality can be shaped over time.