Why do humans get "goosebumps" when they are cold, or under other circumstances?

This video may give you an idea to how we get goose bumps – the weird and wonderful science behind them. When you’re cold, or you experience a strong emotion, such as fear, shock, anxiety, sexual arousal or even inspiration, goosebumps can suddenly pop up all over the skin. They occur when the tiny muscle located at the base of each hair follicle contracts, causing the hair to stand on end. Goosebumps have many different names in different countries