Punk is the personification of anti-culture, anarchy and revolution. It has a unique image and a rather cult/iconic status. For those of you that have seen 'This is England' may have an idea of what Punk is.
So can an image formulate an attitude. Images formulate opinions, especially by others. We judge what we don't know and we stereotype. If she has a mile high mohawk or he has more chains than a bicycle through his face, they must be bad. They couldn't possibly be friendly or civil.
Why not?
We are a culture of judgers. We see what we want to see. Nobody has the freedom to express themselves. Not unless they wish to be judged. While Punk is a particular example, it applies to most alternate things. That of a different mindset. Often a more free and liberal one. While many subcultures are powered by music, a fashion element has to come in too. You should like the clothes if you wear them. You also need to feel comfortable and confident in them. If you don't, your lack of confidence will show, trust me!
As far as an attitude goes,Punk is a great example of two prevailing attitudes (Again, watch 'This is England'). One being the fashion and music side. The other being the political side of things. This is where the anarchic, revolutionary and at times, Nazi elements come in. A music can make you feel one way but does not necessarily make you go and be an anarchist. It is just a song. For others, it does exactly that. Think of it as a lay and active population.
So while one may wear one thing, they may act another. We can judge but I always give someone a chance, at least. There has been times when the most punked up person in the world was on a bus. I'm sure to some he looked scary. But he gave up his seat for an old lady and was talking to some kid about why he had paint and spikes on his jacket :)
Its all about perception. Surely the most ant-expectancy you could do is dress like the end is nigh but be the most friendly, genuine and chatty person in the world!