Smacking your child - or spanking to the US - when they misbehave could make increase the risk of bad behaviour in later childhood, according to a new study.
Researchers analysed the discipline habits of 1,933 parents across the US, and compared their child's behaviour in later childhood.
In total 57% of mothers and 40% of fathers engaged in smacking when children were age 3, and 52% of mothers and 33% of fathers engaged in smacking at age five.
Maternal smacking at age five, even at low levels, was associated with higher levels of child externalising behaviour - such as verbal and physical aggression - at age nine, even after an array of risks and earlier child behaviour were controlled for.
Father’s high-frequency smacking at age five was associated with lower scores on the vocabulary test at age nine.
“Spanking does make the kid stop,” said lead study author Michael J. MacKenzie, associate professor at the Columbia School of Social Work. “It gives the immediate feedback that it’s working. But the goal is to have kids regulate themselves over time. And in that, spanking fails.”
NSPCC's Phillip Noyes believes that smacking children is not the answer to effective discipline.
"We all accept that parents have to be in charge and that clear and consistent boundaries are essential for children and young people to have a secure and happy childhood," he told HuffPost UK Lifestyle.
"But evidence shows that smacking is not an effective form of punishment and sets a bad example, especially for children who have a troubled past as in this story line. It teaches children that violence is an answer and it undermines the trusting relationship between a child and their carer."
Mother-of-two and HuffPost UK blogger Melanie Batley agrees.
"I punish my children because I think it is a necessary part of moral training, and central to creating well-behaved, moral, secure, and happy children," she writes in her blog entitled Parents Need a Smack, Not Their Children.
"I don't want to humiliate or shame them, undermine their sense of self worth, or ever let them doubt that I love them. I want to teach them. I punish to train and reform."
"But punishment is just one tool in discipline," she adds. "Effective discipline also relies on positive reinforcement and love. (A child who is actively praised when they do good is less likely to be motivated to misbehave.)"
Smacking is currently legal in the US, with certain restrictions varying from state to state, but is banned in 20 European countries including Germany and Spain.
Although smacking your child is not illegal in the UK, there are ‘reasonable chastisement’ rules that came into place in 2004 which means that any physical contact cannot leave a mark on the child's skin.
The Fragile Families and Child Well-Being Study, a longitudinal birth cohort study of children in 20 medium to large US cities, was used. Parental reports of spanking were assessed at age 3 and 5, along with child externalising behaviour and receptive vocabulary at age 9 (N = 1933). The data set also included an extensive set of child and family controls (including earlier measures of the child outcomes).