The US Department of Justice released the final report on school violence and showed that middle school is the age when violence is high, accounting for more than 70% of all violence cases (Zweig et al., 2013). After having perpetrated, the probability that the perpetrator will commit violence again will increase significantly (Office of the…

A series of experiments on operant variability by Neuringer and colleagues (e.g., Neuringer, 1986, 2002; Page & Neuringer, 1985) have been repeatedly cited as showing that behavioral variability can be reinforced by making reinforcement contingent on it. They showed that the degree of variability in pigeons' eight-peck sequences, as measured by U…