Administrators have cracked down on physical aggression in schools, enforcing zero tolerance policies for fighting between students.

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"Technically, that would be torture, in some cases, because that's physical aggression against a prisoner, " Mr Mudd says.

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Juvonen's study, however, found boys and girls spread rumors to boost their social status -- and that both genders use physical aggression to assert power.

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The most prevalent challenging behaviour was verbal aggression (cited by 77%), followed by physical aggression (57%), bullying in person (41%) and breaking or ruining other pupils' belongings (23%).

BBC: Disruptive behaviour rising, teachers say

Juvonen and her team recently followed more than 1, 800 students through seventh and eighth grade to determine how physical aggression and the spreading of rumors played a part in social prominence.

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In its annual statement, the trust revealed that during 2005-2006, there were a total of 290 incidents of physical and verbal aggression by the public to its crews.

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