It’s difficult to work out whether China’s decision to end its one-child policy and allow couples to have two children for the first time in 35 years will have a significant impact on the neurobiology of the nation.
While firstborn children are statistically more likely to be successful, there is actually little hard proof that birth order affects behaviour. This is surprising for neuroscientists, as well as parents, as early childhood experiences determine how the cortex of the brain is laid out. In general, firstborns receive more eye contact and direct speech than their younger siblings, which can affect how they relate to and see their place in the world.
Only children in China are sometimes called ‘little emperors’, and indeed with no brothers and sisters around there’s less evolutionary incentive to co-operate, as they have less genetically in common with their closest peers.
Parents may also see an only child as their one chance to pass on their genes to the next generation and therefore lavish even more attention on their little darling. Personally, I think it’s probably quite healthy to be ignored a bit.
Dr Daniel Glaser is director of Science Gallery at King’s College London
