Predicting Penalties

According to a study done at the University of Iowa coaches can accurately predict the number of penalties high school players will commit by giving a questionnaire at the beginning of a season. The study was called "Trait Aggressiveness and Hockey Players: Predicting Hot Tempers on the Ice," and can not only predict the numbers of penalties but also the type. They broke up the types of penalties as aggressive (slashing, roughing, tripping, et cetera) and non aggressive (too many men, no mouth guard, delay of game, et cetera) however, what they discovered was that players who tended to get aggressive penalties overall also tended to cause/get non aggressive penalties as well. Which leads one to suspect that players who are intent on getting someones number, are frustrated and distracted, and will hurt their team with both aggressive penalties and non aggressive penalties. This is what every coach is referring too when they say "we can't afford to take these stupid penalties..."