What makes someone your sister or brother? No easy question in 2005

Researchers delving into today’s complicated range of family set-ups must recognise that ‘brother and sister’ relationships are now about far more than blood ties and living in the same home, warns a new study sponsored by the ESRC.

As 21st Century children and young people create their own, complex understandings of who and what is a sibling, the important social implications need to be taken on board, says a working paper from a team led by Professor Rosalind Edwards of the London South Bank University.

The study found that, for many, the definition of brothers and sisters has less to do with biology and living arrangements than with their own circumstances and experiences. Professor Edwards said: “The increasing diversity of family structures in most western societies raises a number of issues around the technical fact of who is a sister or brother.

“Rising rates of divorce and separation, re-partnering and step-families, mean that children may now have full siblings (sharing both biological parents), half siblings (sharing one) and step-siblings (who are not related by blood, but each has a biological parent in a relationship).” But, she added, this diversity is rarely picked up when official statistics are collected on children and families.

The working paper says that the question of who is a brother or a sister may seem to have a simple answer – siblings are related by biology, through their parents, or at least one of them.

Professor Edwards said: “This is often an assumption underpinning statistics. However, our research reveals that children’s own answers to the question are more complex.

“For children, sibling relationships are built through everyday communication – such as talking, playing and doing activities together, and sharing experiences – or indeed the lack of it.”

The paper says that figures collected by official bodies, notably government, about the number of children living in families, are overwhelmingly collected from the point of view of the family as a household unit, rather than from that of the child.

But separated parents and re-partnering can mean that children do not necessarily live in the same household as their full biological siblings. They may also have half or step-siblings living in the same or another home.

And there can be others – full, half or step – who are no longer dependent, or are looked-after and live elsewhere.

The paper says that looking at the children themselves rather than households, the average number of siblings per child may well be higher than suggested by the figures for those living under one roof. But, it points out that there are no statistics available that allow such an estimate to be made.

Previous studies have shown that the definition of who is a sibling may differ between ethnic and cultural groups. For example, African-Caribbean and African people may view a range of biologically and non-biologically related family members as siblings, and research in the USA focuses on the longstanding practice of ‘going for kin’ amongst African-American communities. In this, non-blood relations regard each other as brother, sister, mother, father and so on.

Professor Edwards said: “This raises the importance of such things as culture, language, and social and emotional experiences in deciding who is a sibling, rather than the self-evident biological or legal position. Being a sibling is a socially built relationship, not just a technical fact.”