In a classic case of researchers mistaking association for causality, a recent widely publicized Ohio State study discusses how the survival of marriages, that is the lack of divorce, seems to be dependent on the number of siblings. The researchers report they factored in the religious affiliation of the respondents and it did not reduce the increasing effect of having more than two siblings on avoiding divorce.
This contradicts previous research which did indicate that religion did influence the longevity of marriage, specifically that marriages with both Jewish partners in California filing for divorce had longer time spans from the point of marriage to the point of filing for divorce than non-Jewish and mixed marriages.
Survival is tracked by following a subject along the trajectory of the life of the phenomenon that is of interest, in this case marriage from the point of nuptials to dissolution or death of a partner. Unfortunately, U.S. studies tracking marriage outcomes do not exist. The difficulty and cost of such longitudinal research which would require following a large enough sample of geographically mobile American adults consistently over their lifetimes to see the outcomes of their marriages.
All the news articles mention that data from interviews of 57,000 adults from across the United States at 28 points between 1972 and 2012 were used. Unfortunately, these were not 57,000 adults interviewed over 28 times over 40 years, but rather 28 yearly cross-sectional adult random national samples averaging about two thousand ever-married respondents each year from the General Social Survey (GSS) data gathered by the the University of Chicago based National Opinion Research Center (NORC).
What the Ohio State researchers, Donna Bobbitt-Zeher, Douglas B. Downey and Joseph Merry, might have found is that having the social support of more than two siblings is an important factor in increasing survival, or life spans, overall. The likelihood of having social support increases with the shared resources of a greater number of siblings. Perhaps the dynamics of shared resources of one or two siblings aren’t enough. Perhaps when the shifting coalitions of the magic number of three or more siblings is reached is when significant family mutual support kicks in.
What the Ohio State researchers likely encountered is that with each succeeding GSS cross-sectional sample of the 28 over 40 years that they actually studied, is that survivors with three or more siblings were much more likely to be in the GSS national samples.
Historically, the number of siblings is on a decline. So, is marriage survival going to decline? It’s probably still prudent to put more of one’s faith in religious affiliation, specifically Judaism, when it comes to the phenomenon of marriage survival. Having more than two siblings probably brings on a myriad of benefits which ultimately lead to longer, more stable lives, including marriage survival. Siblings are born with. Religion has to be acquired and maintained.
Pini Herman, PhD. specializes in demographics, big data and predictive analysis, has served as Asst. Research Professor at the University of Southern California Dept. of Geography, Adjunct Lecturer at the USC School of Social Work, Research Director at the Jewish Federation of Greater Los Angeles following Bruce Phillips, PhD. in that position and is a past President of the Movable Minyan a lay-lead independent congregation in the 3rd Street area. Currently he is a principal of Phillips and Herman Demographic Research. To email Pini: firstname.lastname@example.org To follow Pini on Twitter: Follow @pinih