Habits are incredibly powerful. Good habits can make people highly successful, and bad habits can ruin people’s lives. Still, it is important to go beyond the anecdotal evidence of the many self-help books on habit, and to take stock of the scientific evidence.

This literature review discusses we discuss how habits are formed, how bad habits can be abandoned, how approach-avoidance training can help adopting good habits and abandoning bad habits, and, finally, how habits can be measured properly.