Final answer:
The excerpts concern developmental psychology, socialization, and the attachment theory, showing various instances of behavior and learning across different life stages, from infancy to adulthood.
Step-by-step explanation:
The provided excerpts depict a range of scenarios related to developmental psychology and sociology, particularly the attachment theory, learning process, and effects of socialization. In the first scenario, Danny's behavior is indicative of a secure attachment style, where he feels safe to explore when his mother is present and seeks comfort from her when she returns. This is a common behavior seen in well-attached children. The second excerpt, involving a trade and the emotional distress of Eliza, is a historical reference to the traumatic experiences of slavery, showcasing extreme instances of social and familial disruption. Similarly, the third scenario illustrates early literacy development as the four-and-a-half-year-old boy demonstrates the ability to recognize and read words. These examples, along with the others provided, all relate to understanding the social and cognitive development of individuals at different life stages.