Elaine Aron, Ph.D., is a research associate at State University of New York, Stony Brook. She is the author of The Undervalued Self along with numerous other books, including The Highly Sensitive Person. She also writes a quarterly newsletter on the topics of sensitivity and of ranking, linking, and the undervalued self. She began probing emotional and relationship problems from the "nature" side with her study of high sensitivity—an inherited trait in 20% of the population. Now Aron turns to the "nurture" aspect, the critical problem of self-worth. She studies how innate ranking and linking behaviors, augmented in response to traumatic defeats, can lead to underestimating one's self in crucial situations.