Final answer:
You are less likely to behave by your attitudes when there is external social pressure to behave otherwise, as this can lead to behavior that contrasts with personal beliefs to conform or reduce discomfort.
Step-by-step explanation:
The question concerns situations where an individual might not act according to their attitudes, specifically in various psychological and social contexts. Within the field of social psychology, attitudes are complex constructs composed of affective, behavioral, and cognitive components. They reflect how we feel, behave, and think toward an entity, such as a person, concept, or object. A strongly held attitude (a), consistency with self-concept (c), and congruence with one's values (d) usually predict behavior that aligns with said attitudes.
However, when external social pressure to behave in a certain way opposes our attitudes, it creates a scenario where individuals might act contrary to their own beliefs. This is due to the influence of factors such as conformity, obedience, and cognitive dissonance which often drive individuals to match their behavior with external expectations to reduce psychological discomfort or to fit in with a group.
Therefore, the correct answer is (b) When there is external social pressure to behave otherwise, as this is the scenario that can lead individuals to behave against their attitudes.