Sam and his young son Hugo wanted to make sandwiches, but Sam realized that they did not have any bread. They decided to go to the store. He memorized a list of groceries he needed (bread, potato chips, soup, mustard, ice cream, ham, and napkins). While shopping at the crowded store, they heard a crash as a large display of stacked cans was knocked over near them. After seeing that other shoppers in the store walked around the mess, Sam made sure that Hugo worked with him to clean it up. When they were ready to check out, Sam showed Hugo how to use the self-checkout lane, and Hugo was able to scan the last three items on his own. When Sam got home from the store, he realized he forgot the mustard.

Explain how the following relate to the scenario.

• Bystander effect
• Basilar membrane
• Altruism
• Serial position effect
• Erik Erikson's stage of autonomy versus shame and doubt
• Drive-reduction theory
• Zone of proximal development