Habits are solutions to recurring environmental problems, with examples including going for a run, playing video games, or smoking a cigarette after a long day.

“Habits are solutions to the recurring problems in our environment. Let's say you get done with a long day of work. You come back, you're kind of exhausted. That happens, you know, frequently. It's a recurring problem that you face. How do you solve that problem? One person might solve it by going for a run for 30 minutes. Another person might solve it by playing video games for 30 minutes. Another person might solve it by smoking a cigarette. They all are trying to solve that same core problem.”