NCDS challenging stereotypes of only children

Family background matters more than being an only child when it comes to children’s development, according to evidence from NCDS and three other cohort studies.

Many people believe only children’s cognitive development – the growth of knowledge, skills, and problem solving – outpaces their peers. The reason, supposedly, is that only children don’t have to share their parents’ attention and the family’s resources with brothers and sisters. As a result, they receive more attention and resources themselves, which in turn furthers their development. But is this really the case? 

What we asked you 

When you were 11 years old, you completed special exercises in which you were asked to choose the appropriate word to complete the sentences.  

Your mothers also told us if you had any siblings living with you at home. 

What the researchers found 

CLS researchers compared results on these word tasks from those who grew up with siblings at home to those without siblings. They found that, across all generations, only children had no advantage over those from two-child families in these assessments at age 11. However, only children did do better than children growing up in households with three or more children.

Instead, things like divorce or financial struggles were more likely to impact children’s cognitive development than whether they have brothers and sisters.

How are families changing? 

Although only children did do better than children with two or more siblings, this so-called ‘advantage’ was less common for only children born at the turn of the century. Researchers believe this is because only-child families are changing.

Among your generation, most only children came from better-off homes. Today, only children are a more mixed group, and many have faced difficult experiences like family breakdown.

Why this research matters 

Only-child families are becoming more common around the globe, for a range of different reasons. It’s important to challenge old stereotypes of only children, so their differences are not overlooked in the way we support these children and their families.

This research was covered by The Conversation news site and translated into five languages. It’s reached millions of people around the world, from France, to Singapore, to Brazil!

Read the full research report 

Only Children and Cognitive Ability in Childhood: A Cross-Cohort Analysis over 50 Years in the United Kingdom by Alice Goisis, Jenny Chanfreau, Vanessa Moulton, and George B. Ploubidis was published by Population and Development Review in May 2023.