In order for you to feel at peace, happy, and generally well (as opposed to anxious, on edge, or even in a state of panic), your brain needs a sufficient quantity of “feel good” or “happy” chemicals: Serotonin, Dopamine, Oxytocin, and Endorphin. The most widely used anti-anxiety and anti-depressant medications work by keeping the serotonin you produce around longer than it normally would before it dissipates – this process thereby artificially increases the amount of it in your brain at any given time. Other classes of medication can boost dopamine and oxytocin as well. While these medications work well with minimal side effects for many people, there are also many people for whom they are ineffective or who can not or do not want to tolerate their negative side effects (including lower blood sodium, low libido, weight gain, and many other possible side effects). The good news of this book is that there are regular behaviors YOU can practice to encourage your brain to produce more of all four of these happy chemicals. The book assumes human evolution from lower life forms as well as evolution of humans themselves over time – it consequently suggests that the book’s recommended behaviors were necessary for human survival long ago. Regardless of your perspective on human origins, the good news is that there are practical behaviors you can engage in TODAY to begin increasing your body’s production of these happy chemicals, as well as behaviors you can avoid in order to prevent underproduction and overuse of these chemicals. Like every strategy on this website, this one will likely work best when paired with others.