Pressures to improve test scores and avoid lawsuits are causing many schools to cut back play time. According to the American Association for the Child's Right to play, nearly 40% of the nation's 16,000 school districts have either modified, deleted, or are considering deleting recess. Moreover, where playtime does still exist, it has become overly safe and highly predictable. But according to experts, play makes children more resistant to chronic illnesses since they become more physically active and fit. Also, rough-and-tumble play is how kids learn social skills, how they learn to inhibit aggression, and how to recognize aggressive facial cues. Lack of playtime increasing regulation of what playtime does exist contributes to the childhood obesity crisis, harms children by removing an outlet for creativity, and is a factor in impulse control problems like ADHD (attention deficit hyperactivity disorder).