041: Siblings: Why do they fight, and what can we do about it?

Hot on the heels of our last episode on whether only children really are as bad as their reputation, this week’s episode is for the 80% of families (in the U.S., at least) who have more than one child. How do siblings impact each other’s development?  What should we make of the research on how birth order impacts each child?  Why the heck do siblings fight so much, and what can we do about it?  (Turns out that siblings in non-Western countries actually don’t fight anywhere near as much…) We cover all this and more with my guest, Professor Susan McHale of Penn State University.   Note: Professor McHale mentions a helpful book written by Judy Dunn at the end of the episode but doesn’t specifically name the title; Dunn has actually written a number of books on siblings which can be found here.   References Bjerkedal, T., Kristensen, P., Skjeret, G.A., & Brevik, J.I. (2007). Intelligence test scores and birth order among young Norwegian men (conscripts) analyzed within and between families. Intelligence 35, 503-514. Branje, S.J.T., van Lieshout, C.F.M., van Aken, M.A.G., & Haselager, G.J.T. (2004). Perceived support in sibling relationships and adolescent development. Journal of Child Psychology and Psychiatry 45(8), 1385-1396. Dixon, M., Reyes, C.J., Leppert, M.F., & Pappas, L.M. (2008). Personality and birth order in large families. Personality and Individual Differences 44, 119-128. Dunn, J., & Kendrick, C. (1980). The arrival of a sibling: Changes in patterns of interaction between mother and first-born child. Journal of Child Psychology and Psychiatry 21, 119-132. Dunn, J. (1995). From one child to two: What to expect, how to cope, and how to enjoy your growing family. New York, NY: Ballantine. Feinberg, M.E., Solmeyer, A.R., Hostetler, M.L., Sakuma K-L, Jones, D., & McHale, S.M. (2012). Siblings are special: Initial test of a new approach for preventing youth behavior problems. Journal of Adolescent Health 53, 166-173. Healey, M.D., & Ellis B.J. (2007). Birth order, conscientiousness, and openness to experience: Tests of the family-niche model of personality using a within-family methodology. Evolution and Human Behavior 28, 55-59. Jensen, A.C., & McHale, S.M. (2015). What makes siblings different? The development of sibling differences in academic achievement and interests. Journal of Family Psychology 29(3), 469-478. Kristensen, P. & Bjerkedal, T. (2007). Explaining the relation between birth order and intelligence. Science (New Series), 316(5832), 1717. Lawson, D.W., & Mace, R. (2008). Sibling configuration and childhood growth in contemporary British Families. International Journal of Epidemiology 37, 1408-1421. McHale, S.M., Bissell, J., & Kim, J-Y. (2009). Sibling relationship, family, and genetic factors in sibling similarity in sexual risk. Journal of Family Psychiatry 23(4), 562-572. McHale, S.M., Updegraff, K.A., Helms-Erikson, H., & Crouter, A.C. (2001). Sibling influences on gender development in middle childhood and early adolescence: A longitudinal study. Developmental Psychology 37(1), 115-125. McHale, S.M., Updegraff, K.A., & Whiteman, S.D. (2012). Sibling relationships and influences in childhood and adolescence. Journal of Marriage and Family 75(5), 913-930. Palhaus, D.L., Wehr, P., & Trapnell, P.D. (2000). Resolving controversy over birth order and personality: By debate or by design? Politics and the Life Sciences 19(2), 177-179. Rohrer, J.M., Egloff, B., & Schmukle, S.C. (2015). Examining the effects of birth order on personality. Proceedings of the National Academy of Sciences 112(46), 14224-14229. Solmeyer, A.R., McHale, S.M., & Crouter, A.C. (2014). Longitudinal associations between sibling relationship qualities and risky behavior across adolescence. Developmental Psychology 50(2), 600-610. Updegraff, K.A., McHale, S.M., Killoren, S.E., & Rodriguez, S.A. (2011). Cultural variations in sibling relationships. In J. Caspi (Ed.), Sibling Development: Implications for Mental Health Practitioners. New York, NY: Springer.   Read Full Transcript Transcript Jen     [00:38] Hello and welcome to the Your Parenting Mojo podcast. Regular listeners will recall that this is the second episode in a two part series, which was prompted by a listener emailing me to say that she and her partner don’t want to have another child, but they’re worried about the impacts of not having siblings on their daughter. We looked at that topic last week, but I didn’t think it was fair to the other 80 percent of the families in the country, assuming all of them are listening who have more than one child. So today’s episode is for all of you. I’d like to extend a warm welcome to my guest, Susan McHale, Distinguished Professor of Human Development and Family Ptudies and professor of Demography – among other things – at Penn State University. Research in her lab focuses on family systems, dynamics including youths and parents, family roles, relationships and daily activities, and how these are linked to family members’ psychological and physical health and development. Her lines of research includes sibling relationships, family, gender dynamics, and the sociocultural context of family dynamics. And since we’ve already done episodes related to those second two topics, I’m especially interested to learn about how all of these come together and are intertwined with the idea of siblings. Welcome Professor McHale. Dr. McHale:    [01:47] Glad to be here. Jen:   [01:48] All right, so I wonder if we could kind of start at the end in a way with the developmental outcomes of signaling relationships and then work our way back to the beginning because there’s way more research on the developmental outcomes than I could have imagined. I wonder if you could summarize some of the state of the current research on several different things and we can kind of work our way down a little list that I have here. I’m the first one being risky behavior like adolescent sex. I had no idea that siblings was related to that. Dr. McHale:  [02:17] Right. Most of the research has been on sibling resemblance and of course siblings are genetically related; it’s not just a social process and some work has been trying to disentangle the role of shared genetics and shared environments in sibling similarity and all kinds of risky behavior from substance use to adolescent sex. I don’t think there’s quite a definitive answer. Usually behaviors are complex and so multiply determined so there’s likely to be some genetic load and some socialization between siblings as well as growing up in the same family that all come together in helping to explain sibling resemblance. In our research, we’ve tried to study the processes through which siblings become more alike or more different from one another by actually asking siblings whether they try to be like one another or whether they try to de-identify or work to be different from their siblings, try to be different because they don’t want to be the same kind of person that their sibling is and what we see is that in sibling relationships that are warm and positive, siblings are more likely to say that they try to be like one another and so on the one hand a positive sibling relationship has good outcomes because siblings can be sources of support, affection and so forth. On the other hand, if you have a sibling who’s really into risky behavior, a warm and close sibling relationship isn’t always a good thing. Jen:   [03:56] And so you see the warm relationship leading the, I assume usually the younger child to model the older child’s behavior? Dr. McHale:    [04:04] Correct. So constructs like partners in crime, older siblings being gatekeepers to availability of substances or relationship partners. These are all ways that siblings can influence one another. Jen: