What causes balloons to make our hair go static?

Question: What causes balloons to make our hair go static?
- Keywords:
  balloon,
  electricity,
  hair,
  static
Asked by bealeewh to Stu, Martin, Mark, Jenni, Helen on 18 Jun 2011.
- Mark Burnley answered on 18 Jun 2011:
  
  This requires rubbing the balloon on something first. After that, you can make your hair go static and even stick the balloon to a wall. This happens because rubbing the balloon rubs off some of the electrons, “charging” the balloon. Because unlike charges attract, the balloon is attracted to the hair or any other object that is not charged (like the wall).

Question: What causes balloons to make our hair go static?