"Spanking naughty children increases their risk of depression and becoming hooked on illegal drugs, a new study confirms," the Mail Online reports.
The news comes from the results of a US study that included a sample of more than 8,000 Californian adults.
Researchers asked simple questions about people's current mental health, and asked if they'd ever been smacked as a child or experienced other forms of physical or emotional abuse.
Smacking was defined as "use of physical force with the intention of causing a child to experience pain, but not injury".
In general, the researchers found people who said they'd been smacked as children were more likely to report having problems like symptoms of depression, drinking moderate or heavy amounts of alcohol, and taking drugs.
The researchers made the case that smacking in childhood could have the same long-term negative impact as traumatic life events, such as being sexually abused or parents getting divorced.
But because of the nature of this study, a cause and effect relationship hasn't been proven, no matter how plausible the link might seem.
This means the study doesn't provide strong evidence that smacking causes adverse mental health outcomes – but nevertheless, there is a link between the two.
According to the charity Child Law Advice, the current law in the UK is that, "It is unlawful for a parent or carer to smack their child, except where this amounts to 'reasonable punishment'."
It's fair to say that while smacking as "reasonable punishment" may be legal, whether any form of physical punishment is acceptable is something widely debated by paediatricians and child development experts.
The study was carried out by researchers from the University of Manitoba, the University of Michigan, the University of Texas, and the Centers for Disease Control in the US.
No sources of financial support are reported.
The Mail's reporting of the study was accurate, but the headline – "Spanking naughty children… 'should be considered as bad as going through a divorce'" – might give the impression this is a proven fact when this is actually only the researchers' opinion.
This cross-sectional study of US adults aimed to see whether their childhood experiences of smacking were linked to their current health.
Much research has looked at how adverse childhood experiences may be linked to poor health outcomes.
Adverse experiences can take many forms, varying from parental separation or illness in a close family member to maltreatment, neglect and abuse.
Past studies have rarely included smacking as an adverse experience, even though it's still a widely used form of child discipline in many countries.
Smacking is typically defined as "the use of physical force with the intention of causing a child to experience pain, but not injury, for the purpose of correcting or controlling the child's behaviour".
But the design of this study has several limitations when exploring the question of whether smacking causes adverse adult outcomes.
It's difficult to isolate the effect of a single childhood experience, as many other factors could be involved.
It may also be possible many people involved in the study experienced recall bias, as they were asked about childhood events when they were adults.
For example, adults with an alcohol or drug problem may be more likely to remember times they were smacked as a child compared with adults who don't have any of these types of issues.
This US study used self-reported data from adults taking part in the CDC-Kaiser ACE (Adverse Childhood Experience) study.
The study included 8,316 adults, who were recruited when attending routine health checks in California.
They were asked: "Sometimes parents spank [smack] their children as a form of discipline. While you were growing up during your first 18 years of life, how often were you spanked?"
Smacking was defined as "yes" if the person said they were smacked a few times a year, many times a year, weekly or more.
One or two smacks over the course of an entire childhood was defined as not having been smacked.
Participants were also asked about physical or emotional abuse.
This included asking while growing up how often a parent or adult in the home:
Again, this was scored by frequency.
The researchers then assessed adult mental health, which included asking about possible:
The researchers looked at links between smacking and adult mental health outcomes.
They took account of potential confounders like age, gender, ethnicity, educational level, and marital status.
About half of the sample reported having been smacked. Researchers noticed certain trends in the data.
For example, women were more likely to report being smacked than men, and black participants more often than white.
People who reported smacking were more likely to report having symptoms of depression, moderate to heavy drinking, street drug use, or having attempted suicide than those who didn't report having been smacked as a child.
Reports of child physical or emotional abuse were also linked with these outcomes.
The researchers tried to adjust their analysis with smacking for reports of physical or emotional abuse to try to isolate the effect of smacking alone.
They found smacking was still independently linked to an increased likelihood of reporting moderate to heavy drinking, street drug use and attempted suicide, but there was no longer any link with symptoms of depression.
The researchers said that, "Spanking [smacking] is empirically similar to physical and emotional abuse, and including spanking with abuse adds to our understanding of these mental health problems.
"Spanking should also be considered an [adverse childhood experience] and addressed in efforts to prevent violence."
This study found that smacking can be linked to mental health difficulties in adulthood, just as more recognised forms of physical or emotional child abuse can be.
But it's very difficult to prove a direct relationship and be able to say that smacking causes adverse health outcomes with this sort of study.
And a number of limitations need to be considered:
It's very difficult to isolate the effect of a single factor, such as smacking. For example, the parent or carer may have had alcohol or substance use problems, which may have both increased the risk they would smack the child and increased the risk the child would develop these problems themselves. Or children with poor impulse control, who may be more likely to be smacked as a child, may also be more likely to go on to have drug or alcohol problems.
People who were smacked as children are likely to have experienced widely varying degrees of smacking in intensity and frequency, ranging from a mild tap to an injury associated with bruising.
Adults were asked to remember childhood experiences. This means reports of how often they were smacked may be inaccurate. It's also possible that adults with mental health problems are more likely to recall adverse experiences, particularly if they're trying to identify possible causes.
The study hasn't linked smacking with clear mental health diagnoses. It only asked a few simple questions, and hasn't properly assessed whether the person had a valid diagnosis of depression or alcohol or substance use problems.
The sample may not be representative. It's possible that people with very traumatic childhood experiences were less likely (or possibly more likely) to respond to this questionnaire (which got a 65% response rate). This would have introduced a form of selection bias.
Although the results of this study are only being reported now, the adults were actually questioned 20 years ago in 1997, so their childhood would have been in the 1970s or earlier. Cultural and environmental differences between children of different generations may mean that the findings or potential effects of smacking can't easily be applied to children today.
The study only involved people from one region in the US, so the findings may not be representative of elsewhere.
This means the results of this study don't provide strong evidence that smacking causes adverse mental health outcomes in adults – but it's impossible to create an ethical study design that could answer this question.
In the UK, smacking as a "reasonable form of punishment" is legal, but using unreasonable force is illegal. It seems what can be construed as "reasonable" seems to be quite a grey area.
The charity Child Law says that, "Whether a 'smack' amounts to reasonable punishment will depend on the circumstances of each case, taking into consideration factors like the age of the child and the nature of the smack."
They say it wouldn't be possible to rely on the defence of reasonable punishment "if you use severe physical punishment on your child which amounts to wounding, actual bodily harm, grievous bodily harm or child cruelty."