This is quite the heated topic, especially in parenting circles.
"The researchers looked at a wide range of studies and noted that spanking was associated with negative outcomes consistently and across all types of studies, including those using the strongest methodologies such as longitudinal or experimental designs. As many as 80 percent of parents around the world spank their children, according to a 2014 UNICEF report. Gershoff notes that this persistence of spanking is in spite of the fact that there is no clear evidence of positive effects from spanking and ample evidence that it poses a risk of harm to children’s behavior and development." - Risks of Harm from Spanking Confirmed by Analysis of Five Decades of Research
To read more about these findings, click here.