Spanking naughty children doesn’t work and parents shouldn’t do it, the American Academy of Pediatrics said in a strongly worded policy statement released Monday.

The organization of 67,000 pediatricians called for a ban on corporal punishment in the announcement, saying that research over the past decades shows swatting misbehaving children doesn’t teach them self-control and can make them more aggressive in the long run.

“There’s no positive side to it,” said Dr. Jennifer Shu, speaking on behalf of the academy. “There’s no right way to do it.”

While the national organization has recommended against spanking in the past, there hasn’t been an update to the policy for 20 years, Shu said.

The new policy recommends against “spanking, hitting, slapping, threatening, insulting or shaming.”

Researchers know a lot more now about the impact of physical forms of discipline, including negative effects to brain development, Shu said, adding that it was time to take up the issue again.

Teaching children right from wrong is more effective, according to the policy statement.

“There’s no benefit to spanking,” said Dr. Robert Sege, author of the policy statement. “We know that children grow and develop better with positive role modeling and by setting healthy limits. We can do better.”

The use of corporal punishment to discipline children, however, has long been hotly debated, with parents exerting their right to discipline as they see fit.

“Courts have long recognized parents’ fundamental right over the education, discipline and upbringing of their children,” said Brad Dacus, president of the Pacific Justice Institute, a conservative legal defense organization. “And we at the Pacific Justice Institute have long been defenders of the rights of parents to utilize corporal punishment as they see fit for their children so long as it’s done in a manner that’s not abusive.”

The issue landed in the national spotlight in 2014 when NFL running back Adrian Peterson was arrested after punishing his son with a tree branch or switch. He was charged with reckless or negligent injury to a child.

His lawyer said he was using his parental judgment, applying the same form of discipline he received as a child. He pleaded no contest to a misdemeanor assault charge.

Spanking, however, appears to be increasingly falling out of favor. In 2012, about 70 percent of parents believed that “a good, hard spanking is sometimes necessary to discipline a child,” down from 84 percent in 1986, according to a Harris Interactive poll.

“With this generation (of parents), we are seeing less and less,” Shu said. “I do think it’s decreasing.”

Nineteen states allow schools to use corporal punishment, Shu said, although California is not among them.

California bans cruel or inhuman corporal punishment against any child, although spanking isn’t necessarily considered cruel or inhuman.

Pediatricians, however, overwhelmingly believe that spanking doesn’t work.

In addition, research shows that hitting, yelling at or shaming children can increase stress hormones, altering the brain, while verbal abuse is linked to mental health problems in preteens and adolescents, according to the policy statement.

A lot of parents will often say that they were spanked or hit as children and they turned out fine, Shu said.

“I’m glad those people turned out fine,” she said, adding that wasn’t the case for everyone. “Those times we didn’t know any differently.”

Jill Tucker is a San Francisco Chronicle staff writer. Email: jtucker@sfchronicle.com Twitter: @jilltucker