Chaotic homes hamper child development

Growing up in a chaotic home could be bad for a child's developing mind.

The New Scientist magazine reported that an association between disorganised, noisy and cramped homes and lower childhood intelligence has been observed before. But whether socio-economic status, genetics or the environment itself is the cause has never been clear.

So a team of researchers at Pennsylvania State University turned to a database of twins born in the UK between 1994 and 1996. By noting differences between genetically identical twins and fraternal twins, who share only half their genes, they hoped to tease apart the influence of genes and environment.

The team collected information about nearly 8,000 three- and four-year-old twins, on socio-economic status, household chaos and cognitive ability, which they measured with quizzes and vocabulary and grammar tests.

The results showed that the homes of wealthier and better-educated parents were slightly more organised. But after controlling for the large genetic contribution to intelligence, the team found that chaos had an influence on cognitive skills independently of socio-economic status.

"It just makes sense," one of the researchers was reported as saying. "If a child is in a really chaotic home, it's hard to imagine that they can learn in a normal way. Their surroundings just aren't subtle enough for them to tease apart the world."

The findings also suggest that when the environment is more stressful, intelligence is more likely to be constrained by genes.