Integrity is defined as being honest and having strong moral principles. It involves truthfulness in both speech and actions, as well as trustworthiness. Developing integrity requires being honest, truthful, and standing up for the truth even when alone. Lacking integrity is shown through relying on others' opinions for self-esteem, hiding things, making too many compromises, and failing to follow through on commitments. Integrity should be developed because it leads to trust, responsibility, respect from others, and authenticity.