Complex sentence: Federal statistics consistently show that around 80% of school paddlings in the U.S. are of boys, most likely because boys exhibit more often than girls the kinds of misbehaviour for which corporal punishment is thought appropriate.
Split into simpler sentences: Federal statistics consistently show that around 80% of school paddlings in the U.S. are of boys. This is most commonly thought to be because boys, more often than girls, exhibit the kinds of misbehaviour for which corporal punishment is thought appropriate.