The document examines physical, cognitive, and psychosocial development in early adulthood, particularly in the 20s and 30s, highlighting changes in physical endurance, sexual responsiveness, and fertility challenges. It discusses developmental tasks such as independence, intimacy, and emotional stability, as well as theories of early adulthood like Erikson's stages and Sternberg's triangular theory of love. Additionally, it addresses issues of cohabitation, mate selection, and various styles and theories of love.