The importance of siblings
Whether you grew up with a bossy big sister, a whiney little brother, or a twin you couldn’t live without, we don’t often consider the roles our sibs play in our lives. “Grownups can have very strong love-hate feelings about their siblings, but adults don’t always recognise how formative those childhood relationships were,” says Laurie Kramer, PhD, a clinical psychologist and Professor of Applied Psychology. She adds that science has just recently started investigating these dynamics. “There’s been an awful lot of research on how parents – especially mothers – impact the adults their children become, while the influences of siblings has been under-recognised. But when you study siblings you see how powerful those relationships are in terms of shaping the people we end up being and affecting social skills that impact other relationships across our lives.”
Having a unique influence
Part of the power of sibling relationships comes from the fact that they’re different from all other family and social connections. “It’s the longest-lasting relationship in most people’s lives,” says Susan McHale, PhD, Distinguished Professor of Human Development and Family Studies, and Professor of Demography at Penn State University. “It starts in childhood before people meet a spouse or partner and usually ends in late life after parents are gone, so there’s a lot of time for sibling influence.” In addition, growing up together means sharing intimate knowledge about the interior of your family and each other. “Not many people know you like your sibling does,” McHale adds.
What’s more, a sibling relationship often brings different stages together. “Unlike childhood friendships, siblings – unless twins – aren’t the same age,” says Nina Howe, PhD. “So they’re at different levels in terms of development and knowledge of the world, which can come into play as they interact.”
The fights and friendships between young siblings add up to rehearsal for life outside the nest. “The sibling relationship can be a natural laboratory for learning how to get along in the world,” says Howe. This can include figuring out how to engage in positive interplay, testing authority over younger siblings and negotiating disagreements. Of course, such practise can involve negative behaviours, too. A 2014 Developmental Psychology paper co-authored by McHale that looked at the social “training ground” between brothers and sisters reported, “If sibling exchanges are predominantly hostile, then negative interaction patterns are reinforced and the child develops a generalised coercive interpersonal style.”