Shu presented the AAP's findings alongside Dr. Robert Sege, an author of the updated policy Effective Discipline to Raise Healthy Children. She said the evidence shows that spankings do more harm than good when it comes to a child's development.

"We know that the brain does not grow and develop as well once there has been physical punishment to the point where it can cause learning problems, problems with vocabulary and memory, as well as aggressive behavior," Shu said.

Verbal reprimands were found by the AAP to be detrimental to a child's health as well.

"Anything that's verbally abusive in addition to being physically abusive can change the brain architecture," Shu said. "Basically, these are adverse childhood events that can cause toxic stress that can lead to health problems as well as emotional problems as a child reaches the preteen and teen years."

A less harmful way to discipline children effectively would be to reward good behavior and stay consistent with expectations, Shu said.

"Some children might respond to timeouts, a minute per year of age for ages 2 to 5 basically," Shu said. "So sometimes having that timeout to take a break and regroup can help them calm down and then see why that behavior was not good."

Though physical discipline has been part of American culture for generations, Shu said the research is clear — it is time for change.

"I think it's great that so many parents did get spanked growing up and turned out what seems to be OK, but knowing what we do now, we really need to avoid physical punishment because we know that can be harmful," Shu said.

And what does Shu think about the argument that people who received spankings as kids turned out fine? She compares it to growing up at a time when car seats weren't required for young children.

"There weren't any car seats, for example, when I grew up, [and] we turned out fine — those of us who lived to tell about it," Shu said. "But now that we have safety information and car seats, we do recommend that everybody use them all the time."

Sarah Handel and Cindy Johnston produced and edited this story for broadcast.