Which of the following best defines social influence?

The best definition of social influence focuses on how the presence of peers or others in a social context leads to changes in behavior. This emphasizes the direct impact that individuals in one's social environment can have on actions, choices, or attitudes. Social influence can manifest in various forms, such as conformity, compliance, or obedience, where individuals may adjust their behavior to align with group norms or expectations.

The other options, while related to aspects of social influence, do not comprehensively capture its essence. Inner changes to fit in with a group suggest a more personal, introspective process rather than the external dynamics at play in social influence. External pressures reference factors that may affect decision-making but do not encapsulate the complete scope of social influence on behavior that includes both the implicit and explicit aspects of peer interaction. Therefore, the definition that specifies changes in behavior due to peers best captures the core idea of social influence.