The power of habit is a book by Charles Duhigg. The author explores why habits exist and how they can be changed. He includes anecdotes on companies and individuals who struggle to change and who seem to make the change overnight. The author argues that most of the choices we make today seem to be well considered decision making but are in fact just habits. By understanding how habits work, we can rebuild those patterns in whichever way we choose.
Researchers have found that an organ inside the brain is responsible for forming habits called basal ganglia  They studied rats running through a maze to form their opinions on how rats internalize the maze. Converting a sequence of actions into an automatic routine is called chunking. There are dozens if not hundreds of behavioral chunks and they happen because brain is trying to figure ways to save effort. The process is a three step loop involving a cue, a routine and a reward which when repeated becomes a habit. Some peoples habits are obnoxious. If we want to create new habits we should look at Claude C Hopkins who was in the advertising industry and had  a set of rules he coined to create new habits among consumers. Among his rules, he first created a craving to a power of habit. He illustrated this by making
America brush with pepsodent.  The cue he used was a tooth film which was universal and impossible to ignore. He was selling a sensation.To understand next how to change the habit, the author illustrates the golden rule with the example of Tony Dungy who as a coach wanted to change the behavior of the players. Dungy wanted to attack only the middle step in how habits form - the routine. The cue and the reward are kept the same but the routine is changed. When this rule is applied correctly, even habits can be reversed.