BROOKLYN - A school psychologist is providing some insight into the behavior of the group of teenage girls involved in a vicious fight at a McDonald's in Flatbush. 

Psychologist Sue Lotto is dismayed watching cellpohne video of the attack from March 9, which went viral. She says what strikes her most is the amount of anger the girls display. 

Based on her experience, Lotto believes at least half of the girls have what she describes as conduct disorders. These are behaviors that range from truancy, stealing and animal cruelty, to setting fires, being vindictive and promiscuity. 

Lotto says that while she doesn't specifically know anything about any of the teens, she would bet that they have been in trouble before. She adds that they may have repressed feelings from being abused or neglected themselves, and have likely shown a lack of empathy, even with their own families. 

Police have confirmed that 16-year-old Aniah Ferguson, who was the first girl to be arrested, has a history of run-ins with the law, including allegedly stabbing her brother last month. 

According to Lotto, girls like these need more after-school programs, parental involvement and zero tolerance when they break rules, fight in schools or disrespect authority.