Silvan Tomkins was an American psychologist known for his work in the field of affect theory. He developed a comprehensive model of human emotions, proposing that emotions are central to human experience and behavior. His theories emphasized the importance of facial expressions and their connection to emotional responses. Tomkins also contributed to the understanding of personality and motivation. He introduced the concept of "affect" as a primary driver of human behavior, influencing later psychologists and researchers. His work laid the groundwork for further studies in emotion, psychology, and social behavior.