Final answer:
Marcia's theory expands on Erikson's psychosocial development theory by introducing identity statuses.
Step-by-step explanation:
Marcia's theory is more than Erikson's theory because it expands on Erikson's psychosocial development theory. While Erikson focused on the social nature of development and the interaction with others, Marcia's theory introduces the concept of identity statuses. Marcia proposed that individuals go through different identity statuses in their development, including identity diffusion, identity foreclosure, identity moratorium, and identity achievement. Marcia introduced concepts such as identity achievement, moratorium, foreclosure, and identity diffusion to explain different states of dealing with identity concerns. These concepts are generally understood as part of his identity status model, which seeks to understand how personal choices and social interactions influence one's self-definition. This is why Marcia's theory might be considered 'more' than Erikson's in terms of its detailed focus on the aspect of identity. However, it should be noted that "more" can be subjective, and both theories offer valuable insights into different aspects of psychosocial development.