How is it harmful? Are you serious? Have you not kept up to date with research lately?
https://www.psychologytoday.com/blog...s-bad-all-kids
Researchers have looked at effects on three undesirable behaviors in children who are spanked: noncompliance in the short term, noncompliance in the long term, and aggression. This area is hard to study in the home, because spanking rarely occurs at all and rarely in front of strangers. It is hard to study in the laboratory because of the prohibition against hurting subjects.
Researchers have looked at effects on three undesirable behaviors in children who are spanked: noncompliance in the short term, noncompliance in the long term, and aggression. This area is hard to study in the home, because spanking rarely occurs at all and rarely in front of strangers. It is hard to study in the laboratory because of the prohibition against hurting subjects.
Nevertheless, some studies have been done. In one set of analyses with young children in the laboratory, time-outs worked just as well as spanking for (immediate) subsequent compliance on 30 tasks assigned by the mother. Long-term compliance is decreased after spanking (Gershoff, 2002; Gershoff & Grogan-Kaylor, 2013).
In terms of whether parental aggression (spanking) decreases aggression in the child, the answer is no. In fact, spanking tends to increase child aggression: “Spanking predicted increases in children’s aggression over and above initial levels [of aggressive behavior]” and “in none of these longitudinal studies did spanking predict reductions in children’s aggression over time” (p. 134). Instead, spanking predicted increases in children’s aggression.
Why else is spanking harmful?
It undermines trust. Children trust their parents just a little less. They are more likely to step back from the relationship and build a self-protective shield around themselves in terms of relationships generally. Children can learn to mistrust the motives of others and become more threat-reactive in social situations. It can lead to aggressive expectations — they are ready to aggress first before they are aggressed against.
Spanking is harmful for even more reasons, the review indicates:
Spanking destroys mental health.
Spanking increases delinquency and criminal behavior.
Spanking makes it more likely the child will be physically abused.
Just a quick search on google and you can see for yourself.