Once, at a football cup final, a fan friend of a friend spent a good part of the game swearing and arguing at the referee's assistant.  “Lino - you nasty little XXXX” and “Linesman - you XXXXXXX cheat!”  This friend was a respectable pillar of society with a good day job, yet the expectations of being part of a football crowd changed his behaviour dramatically.  

Zimbardo’s famous Stanford Prison Experiment took random people and assigned them to the role of “prisoner” or “guard” in a pretend prison and paid them $15 daily.  Almost immediately, the guards began acting oppressively, demanding press-ups from the “prisoners” and quickly becoming more hostile towards them, forcing them to clean toilets with toothbrushes and such like.  Scheduled for a two week run, the experiment was cancelled after 6 days.

Though criticised, the experiment has been used to show that much behaviour is not down to a person's disposition (they’re naturally angry) but rather is caused by their situation (they're angry all the time because they have no money). 

Creating the right conditions, then, can have a major influence on behaviour.  If children come to a school where poor behaviour is endemic, condoned or expected, they will play up to this role.  If everyone else smiles and says hello to everyone else, most will fall in and behave well.  One example from several I could choose: Cumberland Community School, serving the same community of students it always has, has dramatically improved behaviour in a few years by creating the right conditions and by having high expectations. 

Every day in our schools we work hard to create pleasant learning conditions and shape the expectations of our students and each other.  We define leadership behaviours and expectations and hold each other to account for them.  We expect high standards of behaviour from students and, generally, unlike my friend’s team, we hit our goals.