Human needs psychology teaches us that all human motivation can be explained by the need to meet one or more of these primary needs: 

• Certainty
• Variety
• Significance
• Connection and love
• Growth
• Contribution 

Anytime you are in an interpersonal relationship whether to close a sale or coach an employee, it is important to understand which of the needs (one or many) are motivating the other person. Each need is met differently so take the time to think about it.

Simple concept but very powerful.