Final answer:
Living in groups was advantageous for our ancestors because it increased their chances of survival. This argument is used by advocates of evolutionary personality theory to explain the fear of strangers.
Step-by-step explanation:
Living in groups was advantageous for our ancestors because it increased their chances of survival. In a group, individuals could work together to find food, protect against predators, and raise offspring. This argument is used by advocates of evolutionary personality theory to explain the fear of strangers because humans developed a natural caution towards unfamiliar individuals to ensure their safety.