Final answer:
Chris McCandless called himself Alex to symbolize his personal transformation and desire for a new life, affecting his interactions by creating a sense of detachment from his past and approachability to others.
Step-by-step explanation:
Chris McCandless started calling himself Alex as a symbol of his desire to reinvent himself and live a life that was radically different from his previous one. Adopting a new name can be seen as a form of personal transformation, a way to shed past identities and societal expectations, and emerge as a new individual with different values and aspirations. This name change likely altered how he interacted with others by creating a sense of independence and detachment from his past, casting himself as a solitary figure on a quest for meaning, which might have made him more approachable to strangers due to the lack of preconceived notions about his former life.