Smacking is associated with more aggression, more antisocial behaviour, more mental health and cognitive problems, and poorer relationships with parents, according to the most comprehensive analysis of the research to date. And, it appears that the detrimental effects may also reach into adulthood.
2014 data from UNICEF revealed that around the world, 80 per cent of children are smacked or physically disciplined by their parents. It's a controversial issue and the subject of hundreds of studies documenting the impact of corporal punishment on a range of emotional, behavioural, physical and cognitive outcomes.
The current research, published in Journal of Family Psychology, examined 50 years of work involving over 160,000 children. Defining smacking as "hitting a child on their buttocks or extremities using an open hand" Elizabeth Gershoff of The University of Texas and Andrew Grogan-Kaylor of The University of Michigan, examined a range of studies in an attempt to draw more definitive conclusions about the consequences of physical discipline.
In a statement, Gershoff explained: "We found that spanking was associated with unintended detrimental outcomes and was not associated with more immediate or long-term compliance, which are parents' intended outcomes when they discipline their children."
Specifically, in childhood, smacking was associated with: more aggression, more antisocial behaviour, more externalising problems, more internalising problems, more mental health issues and poorer relationships with parents. It was also linked to lower cognitive ability and lower self-esteem.
Gershoff and Grogan-Kaylor also highlighted the link between physical discipline and physical abuse. "We as a society think of spanking and physical abuse as distinct behaviours," explained Gershoff, of this finding. "Yet our research shows that spanking is linked with the same negative child outcomes as abuse, just to a slightly lesser degree."
As part of their analysis, Gershoff and Grogan-Kaylor also explored the long-term effects of having been physically disciplined as a child. Adults who were smacked were more likely to display antisocial behaviour and experience mental health problems. In addition, they were more likely to support the use of physical punishment when it came to their own children.
"The finding that a history of received spanking is linked with more support for spanking of children as an adult may be an example of intergenerational transmission of spanking, or it may be an example of adults selectively remembering their past as a way of rationalising their current beliefs," the researchers noted.
The authors caution that given a large proportion of the studies they analysed were correlational or retrospective in nature, causal links between smacking and the reported child outcomes cannot be established. "That said," they write, "…we can conclude that the data are consistent with a conclusion that spanking is associated with undesirable outcomes. "
Importantly, Gershoff and Grogan-Kaylor discovered that the association between smacking and these undesirable outcomes did not depend on how smacking was assessed, who reported the smacking, the country where the research was conducted, or how old the children were. Smacking was associated with negative outcomes consistently and across all types of studies.
The researchers conclude that given "there is no evidence that spanking does any good for children and all evidence points to the risk of it doing harm," parents who use it, and practitioners who recommend it, should reconsider doing so.
"We hope that our study can help educate parents about the potential harms of spanking and prompt them to try positive and non-punitive forms of discipline," Ms Gershoff said.