Who used the concept of ‘balance’ in his theory of attitude change?

The correct answer is Fritz Heider.

In social psychology, the concept of "balance" was introduced by Fritz Heider in 1946 through his Balance Theory. Heider's theory is a motivational theory of attitude change that conceptualizes cognitive consistency. It explains how individuals seek to maintain a balanced and harmonious state among their beliefs, feelings, and relationships with other people or objects.

Heider proposed a triad model, often referred to as the P-O-X model, where:
• P represents the person (the focal individual),
• O represents another person, and
• X represents an attitude object, issue, or a third person.

According to this theory, the relations between P, O, and X can be either positive (liking/associating) or negative (disliking/dissociating). A state of balance is achieved when the multiplication of the signs of the three relations yields a positive result. If the system is imbalanced (multiplying the signs yields a negative result), the individual experiences cognitive tension and is motivated to change their attitude toward either O or X to restore balance.