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The good news about spanking is that parents today are less likely to do it to their children than parents in the past. The bad news is that parents today still spank their kids—a lot.

“Some estimates are that by the time a child reaches the fifth grade [in the United States], 80 percent of children have been spanked,” says George Holden, a professor of psychology at Southern Methodist University who studies parenting and corporal punishment. Spanking is also widespread worldwide.

Perhaps parents are quick to spank their children because it can bring about immediate acquiescence, but the benefits, a consensus of scholars and doctors agree, end there. On Monday, the American Academy of Pediatrics (AAP), which represents 67,000 doctors, came out strongly against the practice, saying that it “harms children,” doesn’t change their behavior for the better, and may make them more aggressive later in life.

The first time the AAP, which publishes recommendations on everything from bullying to teens’ sleep schedules, issued guidelines on spanking was in 1998. Those guidelines said that pediatricians should encourage parents to seek out other punitive measures, which remained the organization’s stance until this week. “Now, with the accumulation of two more decades of research, it’s much more clear that parents should not spank their children,” says Robert Sege, a pediatrician at Tufts Medical Center who helped write the AAP’s latest statement. Other research has indicated that spanking is linked to an increased likelihood of anxiety, diminished cognitive abilities, and lower self-esteem, among other things.

Holden says it’s difficult to say exactly how common spanking is, because some surveys measure parents’ beliefs about whether spanking is acceptable (which don’t always line up with their actual behavior) and others tally up parents’ reports of their behavior (which … don’t always line up with their actual behavior). He says it’s clear, though, that “the majority of [American] children at some point in their childhood are hit”—a word Holden uses interchangeably with spanked because, he says, the term spanking can “normalize the act of hitting children.” (The peak years of spanking, he says, are from ages 2 to 5.) Holden also said that academic research points to spanking being more common among those who live in the South, those who have fundamentalist religious beliefs, and those who have less education.

Still, the ubiquity of spanking today represents an improvement over the past. According to the General Social Survey, as of 2014, 70 percent of American adults agreed that a “good, hard spanking is sometimes necessary to discipline a child.” In the mid-1980s, the percentage was in the mid-80s. Holden attributes this decline to the mounting evidence against spanking, and pediatricians who advise parents not to spank.

The AAP’s new guidelines also note “the harm associated with verbal punishment, such as shaming or humiliation,” and indeed, many parenting experts and psychologists have promoted positivity as a way of changing kids’ behavior. Alan Kazdin, the director of the Yale Parenting Center and a former president of the American Psychological Association, has called spanking “a horrible thing that does not work,” and says that what does work is enthusiastic approval of good conduct. “When you get compliance, if that’s the behavior you want,” he told my colleague Olga Khazan in 2016, “now you go over and praise it … very effusively.” The idea is that such praise will encourage better behavior in the future.

One reason it may be difficult to adjust from punishment to praise is that spanking and yelling are, to many parents, cathartic in frustrating moments. Another is that the philosophy behind spanking—essentially, that physical punishment can change kids’ behavior—has a deeper history that’s hard to erase from the culture. “The Puritans believed in infant depravity, and they totally rejected the idea of childhood innocence,” says Steven Mintz, a history professor at the University of Texas at Austin. “They argued that you had to break a child’s will just as you had to break a horse, and physical punishment was viewed as the key to that.”

Later, 20th-century parenting-advice givers as beloved as Benjamin Spock once said that the quick act of spanking could be “less poisonous than lengthy disapproval,” though he revised his position later in life. Now, in the 21st century, doctors and researchers don’t equivocate—but Americans keep on spanking anyway.

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