Smacking children makes them do worse at school and decreases their cognitive abilities, new research has found.
Two US scientists looked at 650 children and their caregivers, mapping the type of punishments they received and their "cognitive outcomes, school engagement, and peer isolation".
Punishments the children received were categorised as either 'mild corporal punishment', 'harsh corporal punishment' or 'physical abuse'.
They found that even if physical punishment dished out didn't seriously injure the child, the recipients experienced "fear and distress", negatively impacting brain structure, development and overall wellbeing.
"This punishment style is meant to inflict minor pain so the child will change their behaviour to avoid future punishment, but it does not give children the opportunity to learn how to behave appropriately through explanation and reasoning," said Sarah Font, assistant professor of sociology at Penn State University and study author.
"Exposure to physical abuse has a significant negative influence on cognitive performance, and harsh corporal punishment notably increases peer isolation in children."
- With Winston Peters as kingmaker, could the anti-smacking law be overturned
- Many Kiwi parents smack their children - study
- PM not keen on smacking referendum
New Zealand removed the legal defence of "reasonable force" for caregivers charged with assaulting their children in 2007. At the same time, using force "for the purpose of correction" was outlawed.
"Considering that mild physical punishment can develop into physical abuse and that even these mild punishments have consequences on children's cognitive and social school functioning, parent education on alternative forms of punishment may be one solution to prevent physical abuse," said Prof Font.
The research was published in journal Child Abuse & Neglect.