Before you spank your child, you may want to think again. Children who are given corporal punishment, such as spanking, are more aggressive towards parents and peers and are more likely to develop antisocial behavior, according to a new study.

Corporal punishment may help in the short-term, but researchers found that across 20 years' worth of studies that punishment is harmful to a child's long-term development.

Virtually without exception, these studies found that physical punishment was associated with higher levels of aggression against parents, siblings, peers and spouses, Joan Durrant, lead author from the Department of Family Social Sciences, University of Manitoba wrote. The study appeared Monday in the Canadian Medical Association Journal.

This study puts into question the policies of states that still allow corporal punishment in schools. In the U.S., 31 states and D.C. ban corporal punishment in schools, according to the Center for Effective Discipline, a non-profit that advocates against corporal punishment.

In states where corporal punishment is allowed, the practice is common. WXIA-TV in Atlanta, Ga., recently found 21,792 cases of corporal punishment occured during in the 2010-2011 school year.

The specific, personal stories that you hear can make you cry, can make you sad -- a lot of damage done to a lot of children, Debbie Seagraves, director of the Georgia chapter of the ACLU, told WXIA-TV. I remember this one where a child was held down and beaten with a wooden board. The skin was broken, the tailboard was broken, and he was hospitalized, she said.

Durrant worked with the Children's Hospital of Eastern Ontario for their research, which consisted of 500 families who worked with the researchers to reduce their use of physical punishment. As their use of corporal punishment declined, so did their child's difficult behaviors. Spanking is legal in Canada, but illegal in schools.

Results consistently suggest that physical punishment has a direct causal effect on externalizing behaviour, whether through a reflexive response to pain, modeling or coercive family processes, Durrant wrote.

Physical punishment has been linked to psychiatric disorders in children and adults, and recent research suggests that corporal punishment slows cognitive development in children, according to Medpage Today. Durrant's study, which looked at previous studies that have been ongoing since 1990, found that corporal punishment predicted later antisocial behavior.

Georgia allows a school board to decide if corporal punishment will be allowed in that district, according to WXIA-TV and spells out some guidelines, such as:

  • The principal or teacher who administered corporal punishment must provide the child's parent, upon request, a written explanation of the reasons for the punishment
  • Corporal punishment should never be used as a first line of punishment.
  • A doctor's note can excuse a child from corporal punishment

Corporal punishment has been the preferred punishment of children as recently as 1992. Durrant wrote that in light of recent research, physicians have an obligation to tell parents that it simply doesn't work.

Physicians have a primary responsibility for translating research and evidence into guidance for parents and children and they are credible and influential voices for advancing public education and policy concerning population health, she concluded.

According to WXIA-TV, the corporal punishment numbers are so high because students and parents prefer it in lieu of other punishments. It's not the assigned punishment, Greg Teems, director of student services for Polk County, Ga., said. A student that had an infraction that was going to go to [in school suspension] for two or three days or go home for [out of school suspension] will request corporal punishment, or a parent will.

Sweden abolished spanking in 1979, and Finland, Norway and Austria soon followed. There are now almost two dozen countries that ban corporal punishment against children.

Canada