Effective discipline of children is a two-way street. Good behaviour relies on a relationship of love and trust between children and parents and other family members.

Children learn to respond to adult authority that is just, loving and consistent and absorb these values in regulating their own behaviour. Parents rely on children's desire to please based on a relationship of love and respect.

These are the basics, played out in many different ways. Neither parents nor children always behave. They can be tired, crotchety and perverse. But if the basics are in place this only serves to round out the learning they gain from this crucial relationship.

Proponents of smacking argue it is not child abuse and that smacking and child abuse are not related issues. They claim that physical punishment is only used as a last resort, that smacking is lightly administered and harmless and should be used when a parent is calm and loving.

But how real is this - what do children tell us? In 2005, as part of my Master's thesis at Otago University, I interviewed 80 children aged between 5 and 14 years old about their experiences and understanding of family discipline. They were from ordinary New Zealand households with no history of child abuse or neglect.

The children's reports contradict some of the commonly held adult claims about the way physical discipline is administered. Most of the children I interviewed said physical punishment was the disciplinary technique most often used in their families, and it was often used as the first line of discipline rather than the last resort.

When asked: "What are some of the things that happen to children when they do things they shouldn't?", some typical responses were: "They [parents] get a stick and smack it [bottom]," (6-year-old girl); "You get a smack in the mouth," (7-year-old boy).

Some 91 per cent of children in this study said they had been physically punished.

Adults may define a smack as something a lot gentler than a hit, but children were clear that a smack is a hard hit that hurts both emotionally and physically.

Smacking made children feel sad, angry and fearful and they said that it spoiled their relationship with the person who smacked them.

"You feel real upset because they are hurting you and you love them so much and then all of a sudden they hit you and hurt you and you feel like as though they don't care about you because they are hurting you," (13-year-old girl).

Fear and pain may sometimes achieve short-term obedience, but in the long term these emotions are unlikely to contribute to positive behavioural outcomes or promote children's effective learning.

Children also reported being smacked for hurting others. Children were told that it was wrong to hurt someone else and yet they are hurt in response to hurting others.

Supporters of the use of physical punishment say that parents should not and do not hit in anger, but children's experiences suggest otherwise.

"Depending on how angry they [parents] are because if it's something they get really angry about then they will probably hit you because they won't be able to control their anger and stuff," (13-year-old boy).

In this context parents may get emotional release and satisfaction from smacking, which may then be confused with effectiveness.

"I think when they [parents] get so angry they just do it [smack] and then afterwards they think, 'Oh I shouldn't have done that'," (13-year-old girl).

Many of the children also described being smacked or hit around the face and/or head and with implements. It is clear that some children's experience of physical punishment is not that of a "mild smack" or "loving tap".

"My Dad uses the tennis racket," (7-year-old boy). "I get smacked in the back of the head with a hand, or I get smacked on the arm with a spoon," (9-year-old girl).

Many of the children believed smacking did not work as a disciplinary tool. They said that the use of time out, having privileges removed or being grounded were far more effective means of discipline.

The children's responses render many adults' claims and justifications highly suspect. It is also concerning that quite large numbers of children reported adult behaviour that was in fact abusive.

One of the hopes of those who supported the law reform was that it would encourage parents who love their children and want the best for them to explore other options for guiding their children's behaviour.

Doing this requires moving on from a number of deeply held and understandable attitudes and emotions - coming to terms with the fact that your own loving parents hit you (they knew no better), that you may have harmed your child's development (it's never too late to change that) and that the law can be regarded as a positive move for children rather than an unwelcome imposition on adults.

Our 2007 child discipline law is only two years old - let's give it time to help New Zealand grow happy, healthy children.

* Terry Dobbs lectures at AUT University in the Institute of Public Policy and is also doing research for Amokura Family Violence Prevention Consortium based in Whangarei.