Intervention Bias: When to Step in and When To Leave Things Along

Nassim Taleb, author of many books—The Black SwanFooled By Randomness, and The Bed of Procrustes—is in the process of writing a new book on Fragility. He's taken the sample chapter down from his website but I thought his thoughts were well worth pondering.

He's taken the sample chapter down from his website but I thought his thoughts on our human bias to intervene were worth pondering.

We humans have a natural, seemingly innate, bias to think that systems do not improve on their own, without our intervention or guidance —coupled with the Aristotelian notion that we ourselves know where things should be going.

The intervention bias is the direct result of our refusal to accept antifragility, manifested, as we saw, in the absence of a direct word for it. So let us examine a broader aspect of the idea with some psychological traits we humans have.

The absence of a direct word for antifragility from main human vocabularies is quite alarming. You can therefore see that the topic of this book is not just antifragility, but also the defects leading to its absence from human vocabulary.

There is a mental defect psychologists call illusion of control that lead to a default to action rather than inaction, even when the benefits of inaction might be greater than those of action. So the intervention bias” (do something seems better than doing nothing, which is fine except that there are cases in which it gets us in trouble). The illusion of control was meant to show how “irrational” (according to some norm of behavior) we humans can be by giving ourselves the illusion to manage the uncontrollable around us: for instance gamblers cannot resist the pressure to do something in order to improve the outcome, such as throw the die with violence when they need a high number, or throw it softly in order to get a low one. Traders cannot resist wearing the same “lucky” shirt (often unwashed) to improve their day and feel they need to find similar way to take control of their destiny. This mental bias leads to all manner of patently “irrational” actions such as belief in paranormal, alternative medicine and many such actions often put under the umbrella magical thinking. Now the irony is that while this bias was devised to expose patently nonscientific fields, it largely affects many things you learn in college, particularly in social science. Many matters we deem scientific are just the fruit of that very illusion of control masquerading as science with, of course, actions to “improve” mankind.

Why is the scientific illusion of control worse than that of the pedestrian version? Because, tout simplement, these gamblers superstitions are benign, not much worse than doing nothing —they may be even beneficial in hidden ways, and in the right environment. But a doctor tinkering with your system or an army playing with a complex system with opaque causal links, say by invading Iraq, giving chemicals to kids and threatening their brain balance, or intervening in the environment, is far worse than nothing.

This variant of the illusion of control leads to the denigration of acts of omission (not doing something, letting things run their own course, leaving nature or the human body alone) as compared to doing something (such as operating on a patient or prescribing medication). This, we will see is the reason medicine used, until recent history, to kill more patients than it saved (and did not even get close to realizing it), and economists of the sophisticated equation-carrying variety, I will hope to convince you, have been particularly harmful to the economic health of societies —central bankers , and finance ministers, by tinkering with economic life, have caused massive instability.

Taleb posted an interesting table regarding intervention bias.