That damned amygdala, which is a little almond-shaped structure that lies deeply embedded in the cerebrum, is one of the most powerful parts of your brain. It controls your behavior, even though you’re not conscious of it. How does it work? When something upsets us, and that something could be a sound, a sight, or just a gut feeling, the amygdala sends notice to our bodies to prepare to fight or flee: the heartbeat speeds up, the blood pressure rises, and breathing quickens. During an argument, you’ll often notice a physical response similar to how you react to fear (for instance, rapid heartbeats and tensing muscles). Recognizing that, your conscious mind (which resides in the prefrontal cortex) can refuse to obey its instructions. Typically, these amygdala hijackings come on fast and dissipate quickly, except in rare cases, such as when a person develops post-traumatic stress disorder from a particularly horrible event or series of events. Knowing how these hijackings work, you know that if you allow yourself to react spontaneously, you will be prone to overreact. You can also comfort yourself with the knowledge that whatever psychological pain you are experiencing will go away before very long.
Reconcile your feelings and your thinking. For most people, life is a never-ending battle between these two parts of the brain. While the amygdala’s reactions come in spurts and then subside, reactions from the prefrontal cortex are more gradual and constant. The biggest difference between people who guide their own personal evolution and achieve their goals and those who don’t is that those who make progress reflect on what causes their amygdala hijackings.
Choose your habits well. Habit is probably the most powerful tool in your brain’s toolbox. It is driven by a golf-ball-sized lump of tissue called the basal ganglia at the base of the cerebrum. It is so deep-seated and instinctual that we are not conscious of it, though it controls our actions.
If you do just about anything frequently enough over time, you will form a habit that will control you. Good habits are those that get you to do what your “upper-level you” wants, and bad habits are those that are controlled by your “lower-level you” and stand in the way of your getting what your “upper-level you” wants. You can create a better set of habits if you understand how this part of your brain works. For example, you can develop a habit that will make you “need” to work out at the gym.
Developing this skill takes some work. The first step is recognizing how habits develop in the first place. Habit is essentially inertia, the strong tendency to keep doing what you have been doing (or not doing what you have not been doing). Research suggests that if you stick with a behavior for approximately eighteen months, you will build a strong tendency to stick to it nearly forever.
For a long time, I didn’t appreciate the extent to which habits control people’s behavior. I experienced this at Bridgewater in the form of people who agreed with our work principles in the abstract but had trouble living by them; I also observed it with friends and family members who wanted to achieve something but constantly found themselves working against their own best interests.