Sibling relationships can often be our most enduring close relationship – so why do we know so little about them?

Claire Hughes

Siblings have a powerful influence on each other’s development – influencing wellbeing, achievement in school and resilience – according to a pioneering 10-year study.

The results of the psychological research project led by Professor Claire Hughes, Fellow and Director of Studies at Newnham College, have been published in a new book, Why Siblings Matter: The Role of Brother and Sister Relationships in Development and Wellbeing.

The children of 140 families were regularly observed at home, nursery and school over a ten year period – the first longitudinal study of its kind. The study started when some children were just two- years-old. A wide range of tests were carried out including observations and assessments to test the children’s aptitude with language, planning skill, memory and control.

The new book covers the way that siblings affect well-being, achievement in school and the repercussions of having a sibling who is ill or disabled. Alongside the new study, the book also covers wider research and explores how positive sibling interactions can be promoted.

Professor Hughes and Dr Naomi White analysed sibling relationships in varied populations such as siblings with disabilities, siblings in different cultures and siblings in non-traditional families.

Professor Hughes, who is also a Professor of Developmental Psychology at the University of Cambridge’s Centre For Family Research, explained: “Although parents are usually the main focus of family influences on children’s well-being, sibling relationships play a significant role in adjustment, above and beyond the contribution of parent-child relationships, and may be particularly important for children facing adversity.”

But why have there been so few studies looking at siblings?

Professor Hughes explained: “Sibling relationships are typically an individual’s most enduring close relationship, but have been much less studied than parent-child relationships, despite the frequent use of siblings in twin studies, case-control studies and widespread interest in birth order effects.

“Sibling research is not as mainsteam as parenting studies. This is possibly because of the belief that the parental relationship with a child is of paramount importance, but this research shows that siblings act as role models, partners in crime and allies. The ‘no-holds-barred’ relationship provides an important context for children to hone fledging social skills and develop the awareness of other people’s thoughts and feelings which is necessary for successful interactions outside the home.”

Why Siblings Matter: The Role of Brother and Sister Relationships in Development and Wellbeing is a Psychology Press Book for Routledge and it is on sale from today (September 29th 2017).

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Listen to the Radio 4 Woman’s Hour podcast featuring Professor Hughes