The research published in the scientific journal Nature Human Behaviour found that there were positive correlations with neurocognition and mental health and being an only child.

Chinese researchers conducted behavioural assessments, brain imaging and socioeconomic and childhood trauma questionnaires.

The study evaluated a group of 7,186 participants aged 18 to 30.

Scientists revealed that only children had better mental health, memory and “superior language ability”.

Only children also tended to be less impulsive and reward dependent, which is linked to needing approval from others.

“More economic resources coupled with heightened parental availability, attention and responsiveness may provide a solid basis for [only children’s] intellectual competence, psychological well-being and mature social behaviours,” the researchers wrote.

The study did not look at outside factors, including interactions from others that could make up for not having a sibling, including cousins and classmates.

Other factors included reasons why families might have only one child like economic factors, infertility or late parenthood.