Free Caveman Logic: The Persistence of Primitive Thinking in a Modern World by Hank Davis

the food.” If I’m in a room full of people who are busy scratching and circling, I’m probably unlikely to discover that the food would have arrived anyway. The bottom line is that we all eat regularly. We survive, we reproduce, and we teach our children to circle and scratch.
    Can the human mind simply accept delivery of an important event—be it positive or negative—without seeing it as a consequence , either of something we have done, or as the bestowal of an external agent? The realistic answer seems to be, “Not easily.” A friend of mine who managed to get into two road mishaps with deer stood out in the road next to her car the second time, crying, “Why me? What did I do wrong?” She wasn’t talking about her driving. An educated and rational person, she found it difficult not to see the accident as punishment for some misdeed, as if the universe (read, God) were monitoring her every thought and action and doling out consequences.
    There is a popular bumper sticker that addresses this problem directly. It says SHIT HAPPENS. Those two words are all but incomprehensible to the majority of people. The sticker does not say I CAUSED SHIT TO HAPPEN. It does not say SHIT WAS DONE TO ME BY A VENGEFUL GOD. It says simply that nonresponse contingent SHIT does happen from time to time. There is no sense looking for what I did to cause it. By excluding any reference to control, that two-word bumper sticker conveys considerable wisdom. But can our cognitive architecture comprehend the message? Again, the most charitable answer is, “Not easily.”
    How might such profound distortions around cause and effect have evolved in our ancestors? You’ll recognize this as the same issue we tackled in chapter 1 when we first considered Type I and Type II errors. Here are the key points:
    1. The perception of cause-effect is crucial to our well-being in the world. This is as true today as it was in the Pleistocene Age.
    2. Cause-effect relationships are invisible. You cannot see a logical (for example, if-then ) connection; you can only infer it from what happens.
    3. Our ancestors who were adept at detecting such causal links were at a reproductive advantage over those who were less skilled at doing so. And better to overestimate than underestimate.
    4. Such a perceptual/cognitive ability would have been part of their brain architecture and available for genetic transmission to the next generation.
    That’s all it takes. And it is reasonable to remind ourselves that errors involving cause and effect do not reflect willful stupidity. They reflect how our minds are predisposed to process information. But more than that, they reflect the fact that there is virtually no incentive to correct these mistakes. Your friends and neighbors also make them.
    One more observation: the causal agents most people manufacture are supernatural. They do not correct our errors of attribution by saying, “I do not exist.” Whether spirits, gods, demons, or dead ancestors, these agents operate on us, the living, by controlling the very things we wish we could control. But there’s a catch: we’ve left a very large and embarrassing clue to the fact that these agents are of our own design. Although they are certifiably supernatural, most of them seem to have the same petty agendas and motives as any human in the village or on the street. “You angered me by doing such-and-such, and so I’m going to get you back.” Our gods and demons and ancestor spirits seem not to be very highly evolved entities. In fact, they are as petty and vindictive as any of us. Perhaps this should surprise nobody since, arguably, we created them out of our own limited imaginations.

INTRODUCING HEURISTICS
    Psychologists use the term heuristics to describe mental shortcuts. Like any shortcut, heuristics can provide great benefits and save lots of time. When they work, it is hard not to admire their elegance. But they do not always work. Often, when they don’t, they