Within-Family Differences Study 
 

History and Mission of the Within-Family Differences Study

WFDS-I

       In 2001, J. Jill Suitor and Karl Pillemer began a program of research on within-family differences in parent-adult child relations with the goal of achieving greater understanding of these processes in aging families. At that time, most research on the causes and consequences of the quality of parent-adult child relationships involved between-family studies of parents' relationships with one child in the family or with all children in the aggregate. The aims of the first phase of the Within-Family Differences Study (WFDS) were to: 1) collect data from members of both generations regarding parents' relationships with each of their adult children; 2) explore the extent to which parents differentiated among their offspring; and 3) identify factors that explained why parents held preferences toward specific children.

       Guided by these aims, between 2001 and 2003 the Center for Survey Research at the University of Massachusetts-Boston was contracted to conduct in-person interviews with 566 mothers (ages 65-75) and 130 of their husbands in person, and telephone interviews with 773 of their adult children. In 299 families, data were collected from members of both generations. Both quantitative and qualitative data were collected from all 1,469 participants. The findings based upon these data revealed that most mothers and fathers differentiated among their adult children across a wide range of relational dimensions, including providing and receiving support, preferences for future caregiving, and emotional closeness. Further, it was possible to identify characteristics of adult children and the parent-child dyad that led parents to prefer particular offspring.

WFDS-II

        The WFDS-I was ideally suited to investigate patterns of within-family differentiation in later life; however, its cross-sectional design did not allow examination of either changes across time in differentiation or the consequences of such differentiation. Thus, building on the findings from the first phase, between 2007 and 2014 the PIs conducted the WFDS-II to examine stability and change in mothers' preferences and adult children's perceptions of those preferences, as well as their effects on mothers' and adult children's psychological and relational well-being.

       Between 2008 and 2009 the CSR at UMB interviewed 420 of the mothers who had participated in the first phase (86% of the original 566 mothers who were living at T2). Between 2008 and 2011, the CSR also interviewed 826 of their adult children, most of whom participated in both the first and second waves of interviews. As in the T1 data collection, qualitative and quantitative data were collected from all 1,246 participants at T2.

       The foci in the WFDS-II were to: 1) explore the stability of the differentiation patterns revealed in the first phase of the study; and 2) investigate the consequences of differentiation on both generations, with particular interest in the experiences of mothers and their adult children when mothers faced health challenges. In this phase of the project, Suitor, Pillemer, and Megan Gilligan (who joined the project in 2006), documented the high stability of mothers' relationships with their children across time, identified the characteristics of adult children and parent-child dyads that predicted which children would assume the caregiver role, and the salience of mothers' earlier preferences in these processes. Further, the team uncovered the detrimental consequences of the violation of preferences regarding future caregivers on mothers' psychological well-being. Finally, the team explored how perceptions of their parents' favoritism affected adult children's relational and psychological well-being, finding that adult children who perceived that their parents favored some siblings over others were more likely to report depressive symptoms, as well as less closeness and greater conflict with siblings.

WFDS-III

        Taken together, the findings of the WFDS-I and WFDS-II demonstrated that among the wide-range of factors researchers have considered in the study of parent-adult child relations, parental preferences emerged as the most consistent predictor of relational and psychological well-being among the mothers and adult offspring in the panel. The researchers expected that such preferences become even more consequential after the loss of parents.

       To explore these issues, Suitor and Gilligan secured funding to conduct the third phase of the project, the Within-Family Differences Study-Bereavement. Between March 2020 and May 2021, CSR at UMB collected quantitative and qualitative data from 543 adult children who participated in the T2 phase, as well as from 454 of their own children over the age of 17 (the grandchildren of the original 566 mothers who participated in T1).  The research team is currently using these data to identify patterns of intergenerational transmission of family relations, including parental favoritism, disfavoritism, and caregiving, as well as explore the roles of long-term parent-child and sibling relations in psychological well-being, physical health, and health behaviors, particularly following the deaths of parents and grandparents.

Contributions of the Within-Family Differences Study

The findings from the study have resulted in more than 70 scholarly publications in scientific journals and edited volumes and have received wide attention in the media. The study has been featured more than 400 times in media reports, including articles in the New York Times, the Boston Globe, the Washington Post, the Toronto Star, the AARP Magazine, and on National Public Radio. Links to the scholarly publications can be found under the tab on the WFDS web site labeled "WFDS Publications". A 2016 Ted Talk based upon the Within-Family Differences Study has been viewed nearly 60,000 times.

TED TALK about the study by Dr. Jill Suitor

 

Acknowledgements

       We wish to express our appreciation for the support we have received for the WFDS. From 2001-2014 and 2019-2021, the project has been supported by grants from the National Institute on Aging (RO1 AG18869-01; 2RO1 AG18869; 1R56AG062767-01). We also express appreciation to the Office of the Vice President for Research at Purdue University for support during the 2014-2015 academic year, and to the Office of the Executive Vice President for Research and the Office of the Provost at Purdue for funding the WFDS-B Feasibility Study in 2017. Jill Suitor and Megan Gilligan also wish to acknowledge support from the Center on Aging and the Life Course at Purdue University.