Hitting children is often seen as an inalienable parental 'right', and an effective parenting technique, but research now debunks these ideas and tells us more about societal dysfunction than our aspirations to raise good people.
So powerful is the evidence, that in 2015 the Council of Europe concluded corporal punishment was a form of torture and urged all member states to ban it.
Last month, Montenegro became the 53rd country to ban corporal punishment of children in every setting. France too, has just passed legislation to stop children being hit by their parents.
Ireland banned smacking in 2015. Irish senator and Former Chief Executive of the Children's Rights Alliance Jillian van Turnhout, co-sponsored the amendment which ended the 'right to hit' in the Republic of Ireland. She says it's about equality:
"Why is it okay to hit a child when you lose control? You wouldn't be allowed to hit your partner, or parents suffering from dementia, so why is hitting a child different?"
A reluctance to change the law in England and Wales persists, despite research suggesting parents know they hit in anger.
An NSPCC poll found that whilst six out of 10 parents with babies and toddlers under the age of four hit their children, 48% admitted the assault was an over-reaction. And yet the right to hit is still seen as a parental prerogative.
Cultural norms allowing violence, seep into government and affect who we elect to champion children and the policies in place to protect them.
David Lammy MP, Chair for the All Party Parliamentary Group On Fatherhood, called on the government in 2012 to ease smacking laws, believing the Summer Riots happened because of a lack of physical discipline. This, he said, left parents, "no longer feeling sovereign in their homes."
There's an irony to Lammy's perspective on smacking children - he hit his own - and the influence he's had on child welfare polices. The very root of corporal punishment lies in Britain's violent colonial past, where the term "reasonable chastisement" originated, the defence that paved the way for the right to hit. It's a pattern of poor thought that's crept into countries dominated by the British Empire.
In 2013, a year after Lammy's call, then Justice Secretary Chris Grayling defended what he called parents' freedom to enforce discipline at home. Grayling, who also hit his children, said it did them good and "sent out a message." None of his comments about corporal punishment, or Lammy's, were rooted in fact.
Research tells us hitting can affect children for the rest of their lives. The Global Initiative To End All Corporal Punishment Of Children reviewed over 250 studies looking at physical punishment, and discovered a disturbing correlation between parental assault and negative outcomes.
These included a high risk of physical harm, acute mental illness, increased aggression and fractured family relationships.
The pro-smacking lobby point out that some children don't experience ongoing difficulties but it's is impossible to know how a child will cope. What is certain is that no evidence exists showing corporal punishment offers any benefits. If we're hitting children to make a point, then the truth is violence is getting us nowhere.
New Zealand's first Children's Commissioner, Dr Ian Hassall sees corporal punishment as a way to excuse parents' violent outbursts:
"We've fallen into the habit of striking children and adopted the excuse that it benefits them in some way but if we're honest it arises from our own poorly controlled frustration and anger. Another excuse is that hitting children is natural but what could be more unnatural than hurting a child? Many families don't do it. Maori did not hit their children according to early reports of European colonists and missionaries. It's a feature of societal dysfunction."
Language plays an important role in how we tolerate violent behaviour. Calling an assault on a child, 'a light tap', or 'a quick smack' diminishes the violence and makes it seem acceptable. Yet lightly tapping or quickly smacking an adult could land you in jail.
Justifying violence on the basis that it's been carried out by someone familiar who loves you is also confusing and traumatic for a child. Dr Tracie Afifi, a professor at the University of Manitoba pioneering research into the effects of corporal punishment is particularly concerned with the paradox of violence in 'safe' emotional spaces:
"When an individual says that corporal punishment is safe if it is done in a specific way they are stating an opinion that is not supported by scientific data. In fact, the data clearly refute this opinion."
The law though, has become better at acting on research. The European Social Charter which the UK ratified in 1962, includes Article 17, which deals with torture. It was this article that the human rights watchdog used to place pressure on Ireland to ban smacking. The Council argued that there was no such thing as "reasonable chastisement" and that beating children was a breach of Article 17 which Ireland had ratified. The UK has also ratified Article 17.
Dr Bernadette Saunders, a senior lecturer in social work at Monash University in Melbourne, says smacking is a child rights issue:
"It's time to recognise children's rights and to provide parents with helpful support that promotes positive parenting, so that responding to children in a violent manner is not even a last resort - even 'just a little smack' is no longer okay."
A ban on all forms of corporal punishment is the next step for the UK, which has tackled domestic violence, child sexual abuse and online exploitation. Having also secured the right to protect children from emotional harm it is irrational that hitting children outright has not been banned, given that emotional and physical abuse are interlinked. The gaping hole in our law which allows us to hit children, is a terrible indictment of how we still view them. It's time we acknowledged children as human beings, and gave them equal protection in the eyes of the law.