People who believe "sparing the rod spoils the child" typically dismiss the enormous body of research showing that hitting children turns them into angry, resentful adults with psychological and emotional problems. A large meta-analysis of studies on the effects of punishment found that the more physical punishment children receive, the more defiant they are toward parents and authorities, the poorer their relationships with parents, the more likely they are to report hitting a dating partner or spouse. They are also more likely to suffer mental health problems, such as anxiety, depression, and substance abuse problems, and less likely to empathize with others or internalize norms of moral behavior.
In a new article, Spanking and Child Development: We Know Enough Now to Stop Hitting Our Children, Elizabeth Gershoff reviews recent research on spanking.
It is also worth noting that the U.S. is relatively unusual in terms of attitudes, prevalence, and legal sanctions. Hitting children is more culturally acceptable in American than in many other nations not only by parents, but by teachers (corporal punishment in schools is still permitted in 19 states). In many nations, physical punishment of children has now been outlawed, even for parents. In the table below, we summarize the legal position with regard to hitting children in a selection of counties.