In previous episodes of this series, we interpreted destructive behaviors like alcoholism and anorexia nervosa as habits that have escaped our normal means of control. Weirdly, these habits have somehow taken on a life of their own, reproducing themselves at our expense. And now they’re relating to us as parasites, using us as their hosts. 

The idea of parasitic habits doesn’t fit anywhere in today’s psychology. But in biology, psychology’s mother science, parasitism is the rule—not the exception. In fact, parasitic organisms vastly outnumber non-parasites. And each animal invests a lot of energy protecting itself from them. If we look with open eyes at the details of our own malignant behaviors, we can see that parasitic forms are common there too. Our willingness to recognize them for what they are is a first step toward crafting a better psychology.