Experts say "popping" kids can do more harm than good. A new study of more than 2,500 toddlers from low-income families found that spanking may have detrimental effects on behavior and mental development. The study found that children who were spanked as 1-year-olds tended to behave more aggressively at age 2, and did not perform as well as other children on a test measuring thinking skills at age 3. The new study focused on children from low-income families because prior research suggested that spanking is more common among them. In addition the study found that parents who spank are more likely to be younger, less educated, single, and/or depressed and stressed. Spanking is most commonly used among parents who were spanked themselves, who live in the South, and/or who identify themselves as conservative Christians.What do you think? Weigh in.