Linda G. Bell is a Professor of Communication Studies and Family Health at Indiana University - Purdue University at Indianapolis (IUPUI). David C. Bell is a Professor of Sociology at IUPUI.

Linda and David have collaborated on this project from the beginning. Linda initiated the project as an NIMH post-doctoral research fellow at the University of Chicago. She designed the projective measure, and directed the instrument development and data collection phases of the project. David has contributed to theory, instrument development, data management and statistical analysis. Linda and David married during college and served in the Peace Corp together in West Africa. Linda's Ph.D. is in Social Psychology from Duke; she studied with Elliot Aronson and Ned Jones. David's Ph.D. is in Social Relations from John's Hopkins. He studied with Jim Coleman and Peter Rossi. The Bells have three children: Michael, Eric, and Claire. Michael is an actor. Eric majored in Japanese and East Asian Studies. Claire, who was born in Japan and joined the family at age five, is interested in working with animals.

Linda G. Bell has been engaged in studying family systems and adolescent development since the 1970s. For 30 years she was also involved in training family therapists, creating and administering a nationally accredited training program in family therapy at the University of Houston - Clear Lake. Her training in experimental social psychology led to a preference for unobtrusive and indirect measures; training in family systems theory convinced her of the need to create system level measures. Her research has enriched and been enriched by her work as a teacher, supervisor, and practitioner of family therapy both in the U.S. and in Japan. This combination of research and clinical experience has been of value both in the development of theory, and in the creation of research instruments and procedures.

David C. Bell has been primarily responsible for data management and statistical analysis over the course of this project. David's theoretical research has included development and extensions of the caregiving process within attachment theory, including the evolution, neurobiology and psychological structure of parental nurturance of children. His empirical research has involved longitudinal analyses of relationship and behavioral change. In addition to collaborative work with Linda, David has studied relationship development over time in the context of the therapeutic relationship in drug abuse treatment, a relationship that is similar to the parent-child relationship in terms of development. He has also studied the social network organization of HIV transmission. David's book Constructing Social Theory will be published in 2008 by Rowman & Littlefield. He is presently completing a manuscript, The Logic of Connection: How Evolution and Biology Create Caregiving and Attachment.