Young children smacked by their parents may grow up to be happier and more successful than those who have never been hit, a study has found.

According to the research, children smacked up to the age of six were likely as teenagers to perform better at school and were more likely to carry out volunteer work and to want to go to university than their peers who had never been physically disciplined.

Only those children who continued to be smacked into adolescence showed clear behavioural problems.

Children’s groups and MPs have tried several times to have physical chastisement by parents outlawed. They claim it is a form of abuse that causes long-term harm to children and say banning it would send a clear signal that violence is unacceptable.

However, Marjorie Gunnoe, professor of psychology at Calvin College in Grand Rapids, Michigan, said her study showed there was insufficient evidence to deny parents the freedom to choose how they discipline their children.

“The claims made for not spanking children fail to hold up. They are not consistent with the data,” said Gunnoe. “I think of spanking as a dangerous tool, but there are times when there is a job big enough for a dangerous tool. You just don’t use it for all your jobs.”

Research into the effects of smacking was previously hampered by the inability to find enough children who had never been smacked, given its past cultural acceptability. But Gunnoe’s work drew on a study of 2,600 people, of whom about a quarter had never been physically chastised.

Gunnoe’s findings were welcomed by Aric Sigman, a psychologist and author of The Spoilt Generation: Why Restoring Authority will Make our Children and Society Happier.

“The idea that smacking and violence are on a continuum is a bizarre and fetishised view of what punishment or smacking is for most parents,” he said.

“If it’s done judiciously by a parent who is normally affectionate and sensitive to their child, our society should not be up in arms about that. Parents should be trusted to distinguish this from a punch in the face.”

Penelope Leach, the British parenting guru whose book Your Baby and Child has sold more than 2m copies, said physical discipline should always be avoided.

“No good can come from hitting a child,” said Leach. “I do not buy this idea that children will learn positive behaviour from being smacked. The law says adults hitting adults is wrong and children should be protected in the same way. Children are people, too.”

British parents have traditionally followed the maxim “spare the rod and spoil the child”. More recently, however, the opposition of children’s charities to smacking has gained support, with 71% of Britons in one poll saying they would support a ban. The law allows smacking as long as it does not leave a mark.

The government says it does not want to criminalise parents for chastising their children with the best of intentions.

Gunnoe’s research included detailed questioning of 179 teenagers who were asked how old they were when they were last smacked and how often they were smacked as a child.

Their answers were compared with information they gave about their behaviour that could have been affected by smacking. This covered bad outcomes, such as antisocial behaviour, early sexual activity, violence and depression, and good outcomes, including academic success and optimism about the future.

Teenagers who had been smacked only when they were aged two to six performed slightly better on almost every positive measure and no worse on the negative measures than those who had never been smacked.

The results were less clear for a separate group of teenagers who had been smacked until they were slightly older — aged seven to 11. They fared slightly worse on negative behaviour scores — they reported being involved in more fights, for example — but were also likely to be more academically successful than those who had not been smacked.

Teenagers who were still being smacked, however, scored significantly worse than every group on all the measures. Gunnoe found little difference in the results between boys and girls and between racial groups.

She is now trying to explain the reasons for the differences. She suggests parents who rule out smacking as a matter of principle may be less likely to help their children develop the self-discipline and social skills needed to succeed in life.