Scientists have found that the brains of only children are structurally different to those in kids with siblings.
Perceived wisdom – and the evidence of nurture’s influence on our personalities – has long pointed to differences in personality between children who have siblings and only children.
Now a new study conducted at the Southwest University in Chongqing, published in Brain Imaging and Behaviour, claims to have proven that these differences are tied in with actual brain structure.
While previous studies have found behavioural differences between only children and children with siblings, this team of researchers tested the grey matter – or brain mass – in participants.
A small cross-section of 250 university students, half of whom are only children, were tested for their personality traits, intelligence, creativity, as well as the anatomical structural differences of grey matter volume, using brain scans.
The study found that “only-children exhibited higher flexibility scores (a dimension of creativity) and lower agreeableness scores (a dimension of personality traits) than non-only-children.”
Furthermore, the team concluded that only children displayed a higher volume of grey matter in the parietal lobe, a part of the brain associated with mental flexibility and imagination.
Conversely, they had less grey matter in the medial prefrontal cortex, a part of the brain known to be involved in thinking about the self in relation to others.
The Chinese study is particularly important culturally, as the country introduced a one-child policy from 1979 to 2015 in order to stem population growth.
While the study points to other research showing only children have tendencies towards popular traits, such as creativity and high intelligence, it also states the environment of one-child families can hinder development of a child’s social skills, emotional support, and empathy.
However, these findings could be biased and serve to perpetuate the stereotypes of only children. After all, both nature and nurture have a huge part to play in the people children grow up to be.