Sales used to be considered the wild west of business operations. Nobody knew exactly which methods made salespeople successful, but everyone was happy when the signed contract landed on the president’s desk. David Hoffeld, CEO of the Hoffeld Group and author of The Science of Selling, has taken some of the mystery out of the selling process. In his recent interview which is available at Knowledge@Wharton, Hoffeld explains that using specific methods, based on science, helps salespeople improve their bottom lines.

Social psychology, neuroscience and behavioral economics all play a role in why a customer will buy from you. Don’t worry. You don’t need to go back to the classroom to learn how to close the deal with your toughest prospect. But, you do need to focus on what motivates her. For example, one principle Hoffeld discusses is the need to “leverage reciprocity” when working with a prospect. The term may sound technical and scientific. In fact, it’s based on a simple concept.

The science of behavioral economics is all about analyzing human behavior to understand economic decision-​making. Your standard approach with a prospect may be to talk to her about the value of the product or service you’re selling. The prospect might not be interested in buying something from you. But, if you give her something of value, even something small, you’ve changed the equation. Behavioral economics and social norms dictate that she now owes you. At that point, she’ll be more willing to listen to your pitch and do business with you.

Give your tough prospect a copy of a white paper or fresh information about a development in her industry. This gesture shows you’ve been paying attention to her business needs, and that you’re willing to give before you receive. Hoffeld notes that  “[r]eciprocity has been shown to boost sales, in some cases, by over 100%.” If you regularly practice reciprocity, you’ll boost your sales, too.