What was the main hair style of the 1920's jazz age?what made the women of the 1920's jazz age cut there hair?

The most usual hairstyle for young women in the 1920s (especially the "flappers") was a very short hairstyle usually called a "bob."

Of course, it is hard to say what made women of that age adopt this hairstyle.  It would be hard to explain why women today wear their hair the way they do.

The usual explanation, however, is that short hair was a way of expressing their new freedom.  During this time, women started doing many things that they had not previously been allowed to do.  In general, they started acting in more independent ways and they started spending more of their lives outside the home.  The short hair was a symbol of this new freedom.