Wendy Hill, professor of psychology at Lafayette College, Pennsylvania began the research to find out why the mundane physical activity of rubbing lips can elicit such a gratifying emotional response.

• 宾夕法尼亚拉法叶大学心理学教授；开始研究为什么摩擦嘴唇样的身体活动可以引起愉悦的情感反应.