Even though spanking has been banned in 32 countries, there are still parents who feel this disciplinary action is helpful in teaching their children right from wrong. However, mothers and fathers may want to consider finding another way of disciplining their kids, as a recent study found that spanking may lower IQ, Reuters reported.

In the study, which was published in the Canadian Medical Association Journal, Canadian researchers reviewed 20 years of research on this form of punishment. They found evidence that children who are physically harmed may face developmental difficulties and cognitive impairment. Recent research has also shown that physical punishment may be linked to a reduction in the brain’s grey matter.

"What we're hoping is that physicians will take that message and do more to counsel parents around this and to help them understand that physical punishment isn't getting them where they want to go," said Joan Durant, one of the study’s authors, as quoted by the news outlet.

In a previous Tulane University study, researchers found that children who were frequently spanked at 3 years of age were more likely to be aggressive by the time they turned 5, Time Magazine reported.

If parents have spanked their children in the past and are curious to see what impact it has had on their cognitive development, they can have them take a kids IQ test.