Sincerity is commonly understood as a reflection of one's inner intentions, but clients cannot directly perceive these intentions. Instead, they rely on external behaviors to gauge sincerity. Actions such as paying attention, showing interest, and engaging in empathetic listening serve as indicators of a person's authentic intentions.

This perspective emphasizes that clients form their perceptions of sincerity based on observable behaviors rather than intrinsic qualities. The book "The Trusted Advisor" by David H. Maister highlights the importance of these external behaviors in building trust and demonstrating sincerity in professional relationships.