Article about Entertaiment:
The word entertainment has come to be closely associated with pleasure and amusement, although it may serve a more serious purpose as in ceremony, celebration, religious festival or satire. It is a form that has evolved and can be adapted to any scale: from a single private act of self-gratification; through an individual choice of the many available pre-recorded products; to banquets adapted for two; to performances intended for thousands and even a global audience.
Entertainment often hits the points the human brain was evolutionarily shaped to react deeply to in order to understand the social world. This includes themes such as backstabbing, murders and other social themes.