Smacking children is now illegal in Scotland after a new law came into force on Saturday.
The defence of justifiable assault has been removed from Scots law – giving children the same protection from assault as adults.
MSPs voted by 84 to 29 to pass the Children (Equal Protection from Assault) (Scotland) Bill at Holyrood last year.
The ban has been welcomed by many charities, however has faced opposition from those who believe parents should be able to discipline their children as they see fit.
Scottish Green MSP John Finnie, the architect of the legislation, said it was a “momentous day for children’s rights”.
He said it would teach children that violence was unacceptable, adding: “Physical punishment has no place in 21st-century Scotland.
“All the international evidence suggests using physical punishment is ineffective, and it can have serious negative impacts on children.”
Charities Children 1st and NSPCC Scotland were among those welcoming the smacking ban. They said it gave “clarity” to parents and that they were “proud” of Scotland for taking the step.
Mary Glasgow, from Children 1st, said: “It takes that notion that you can hit children, you can smack children, off the table.
“It gives a really clear message that children are our most valuable and our most vulnerable citizens and they are afforded the same rights as adults to be protected from physical punishment and assault.
“It brings us to a place where most parents already are where they recognise that smacking children just doesn’t work. It can potentially harm, but it gets in the way of those really loving relationships that we know are so crucial for children if they are to grow up and thrive in Scotland.
“There’s no evidence from any other country that have already taken this really momentous step that it affects the choices that we can make.
“What it does is give clarity and support to parents that there are many more positive ways to help our children grow up to be kind and compassionate and good citizens in a way that doesn’t involve physically punishing them.”
Matt Forde, from NSPCC Scotland, said there was mounting evidence that smacking children did not help improve their behaviour.
He said: “I’m delighted and I’m proud to see us taking this step, and I think we are very much in tune with what children and young people themselves think and what a great many parents think.
“The evidence couldn’t be clearer – physical punishment of children has the potential to damage children. It’s in decline in many countries, including here, because parents are increasingly finding that it doesn’t work.
“International research shows that it’s associated with all sorts of problems for children such as childhood aggression and antisocial behaviour. Children subsequently experiencing depressive symptoms and anxiety, and there is a risk of escalation into abuse.”
However, there remains opposition to the new legislation, with some accusing it of “undermining” parents.
Richard Lucas, from the Scottish Family Party, said he feared children would be unjustifiably taken away from their parents.
Lucas said: “The consequence of it will be that some perfectly decent parents will be landed in very hot water and some children will be taken away from their parents completely unnecessarily.”
The Scottish Government said it was confident the new law would be enforced sensibly.
Children’s minister Maree Todd said: “I would hope that we would have confidence in Police Scotland’s approach when crimes are reported to them.
“Enforcement is only used in a very small number of cases and I think our experience over the last few months confirms that that is the approach of Police Scotland, and I wouldn’t expect this legislation to be any different.”
Police Scotland said officers were undergoing training and that children’s “safety and wellbeing” would be at the “centre of any decision making”.