Q

Butler 'identity is performed through expression'
Your identity is shown by the way you act, talk, walk,dress and the facial/body expressions you show.
So if you have an angry facial expression, and use violent language you can be seen as an aggressive person.

Perkins 'Stereotypes are not always negative'
This quote doesn't relate to what I found in the film i am researching 'Kidulthood'.

It's true some stereotypes are not always negative but from why I've found the stereotype about 'chavs' is and it brands them as working class, lawless an violent people who are uneducated and trouble.
In the film Kidulthood (2006) the characters are seen as teenage 'chavs' who would be described as the above. In the film you see the boys acting violent, reckless, ill mannered and involved withy drugs which relating back to reality young boys especially black boys are see to behave in the same way. Even though one of the girls seems innocent and isn't as loud and confident as her friend she in some parts of the film tries to do right but then get influenced and ends up drinking and doing drugs knowing she is pregnant. So this is showing a young pregnant girl involved in activities seen the be irresponsible and unacceptable which relating back to reality could show that young 'chav' mothers are not responsible or good role models. 

Today the stereotypes for young people living or from estates has never been positive they have always been given bad labels and kidulthood is an example of this, in the film the boys are portrayed as they think they are better than everyone else and those who get the most girls, drugs, money, alcohol and weapons are the ones respected and higher up. They use violence to get messages across and the older boys especially 'harrass' and 'scare' the others into doing whatever they like showing that they give out threatening behaviour and are bullies.

The girls in the film are exactly same, in one scene they are threatening and beating up a frightned and fragile girl giving her bruises and a bloody nose whilst everyone else in the class is just watching this shows that even though they know what the girls are doing is wrong no one wil step up and help as they fear it may backfire onto them because of the way the other girls are behaving resulting in the girl who is getting bullied to commit suicide.
So from these example most stereotypes especially for chavs in Kidulthood stereotypes are strongly negative even if someone is doing good.