Disciplinarians of yore used to strictly adhere to the mantra "spare the rod, spoil the child," but times have changed. Parents who spank their children are few and far between, and most experts roundly reject this form of corporal punishment, branding it as archaic, ineffective and, sometimes, potentially harmful.
Perhaps the biggest reason why spanking is frowned upon is because it instills the idea that violence is a reasonable solution to a problem at a very young age. If one's child learns that they should express anger or frustration in the form of violence it could create behavioral problems further on down the road.
Spanking a child can cause significant emotional harm as well, experts say. The practice might convey to children that it was them, not their actions, that's the problem. This idea can lead to serious self and body image issues. Additionally, it establishes a lack of trust between parents and children at a very young age that can be difficult to regain.
Finally, the most significant reason why dads should never resort to spanking is that it does not work. Numerous studies have shown that any short term benefit is dramatically outweighed by the long term resentment it can foster in kids.