In 1954, conventional wisdom was that if you wanted to raise a spoiled brat, you would never hit your child.

Corporal punishment was considered necessary at home and in school. It was part of the culture – from the Little Rascals to “The Danny Thomas Show.” 

In the musical “Carousel,” when Billy Bigelow comes back to Earth to make amends for his life, he slaps his daughter when she refuses his gift. But then she tells her mother that the slap felt like a kiss, everybody sings “You’ll Never Walk Alone,” and there isn’t a dry eye in the house.

“Spare the rod, spoil the child” was the operative expression. And for some parents, it still is – corporate punishment is not illegal in any American home unless it is excessive. (The problem becomes, of course, what qualifies as “excessive.”)

But starting in the 1950s, attitudes toward corporal punishment began to change.

I don’t have a definitive answer as to why. But I think the one person who might have set off the anti-spanking revolution is Dr. Benjamin Spock.

His watershed 1946 book, “Baby and Child Care,” encouraged parents to cut their kids some slack. He thought affection and treating each child as an individual was a better way to raise them. And though it took a while, parents began to do that.

There were other factors. The kindly ways of children’s show hosts like Fred Rogers and Bob Keeshan, a.k.a. Captain Kangaroo, were at odds with the stern parent image – and may have influenced grownups. And the fact that violence against children – particularly from guns – makes parents more inclined to make their homes a sanctuary rather than a courtroom.

And then there’s science. The American Academy of Pediatrics says corporal punishment leads to a variety of bad outcomes in children – including impaired development, increased aggressiveness and failure to stop bad behavior in the long term.

In 1979, Sweden became the world’s first country to ban corporal punishment in any setting – home or school. Now, 63 nations prohibit it – from Argentina to France to South Korea to South Africa.

In the United States, only four states – Iowa, Maryland, New Jersey and New York – prohibit corporal punishment in all schools. In 27 other states and the District of Columbia, it’s barred in public schools but allowed in private ones. In 19 states – and the Venn diagram of those states and red political states would have a lot of overlap – physical punishment is allowed in public schools.

The idea of hitting someone you love – especially someone virtually defenseless – seems wrong. It seems cruel. 

But hindsight is perfect. Parents of previous generations had the same goal as we do in the 21st century – raising happy, well-adjusted kids. They had a very different way of doing it, because it was all they knew.