Marcia (1966) proposed four ego identity statuses that apply to adolescents based on Erikson's theory: achievement, foreclosure, moratorium, and identity diffusion. Foreclosers tend to have closer relationships with parents while identity diffuse students are more likely to respond to peer pressures. Levinson identified five stages of development across the lifespan: childhood/adolescence, early adulthood, middle adulthood, late adulthood. Vygotsky's sociocultural theory emphasizes that social interactions fuel development and the zone of proximal development refers to what a child can achieve with assistance versus independently.