Can Assumptions Lower Risk?

Mark Galley
President & Root Cause Analysis Facilitator

Conventional wisdom says, “Don’t assume.” The reasoning seems obvious: assumptions can cause us to act on something we have not actually established as true. If we do not have evidence, we should not assume. But does that mean assumptions themselves are the problem?

Certainly, some assumptions create risk. But other assumptions actually reduce it. The important question is not whether we make an assumption. It is what we assume.

What We Mean by “Assume”

The word assume comes from the Latin assumere, meaning “to take upon oneself.” We still use that original sense when we talk about assuming a role or assuming responsibility. By the late 1500s, however, assume had developed another meaning: to take something as true without proof or evidence. When we talk about assumptions and risk, this is the meaning we are using. The Cambridge Dictionary defines assume as “to accept something to be true without question or proof,” and Merriam-Webster similarly defines it as “to take as granted or true.”

But nothing in that definition says the thing being assumed must be good, correct, safe, or as intended. We can assume something is good. We can also assume it might be wrong.

The Mistake Isn’t Assuming—It’s Assuming Things Are Good

There is nothing inherently risky about making any assumption. What’s risky is to assume that something is good, correct, or safe—and then act based on that assumption. For example:

• Assuming the road is clear, so we pull into traffic without looking
• Assuming a communication was understood, so we move on without confirming
• Assuming the medication is correct, so we administer it without checking
• Assuming the phone is charging, so we walk away without getting evidence that it is

But what if we flip those assumptions around? If our objective is to lower risk, instead of assuming things are good, correct, or safe, we should assume they might be bad, wrong, or unsafe. Now the assumption drives us to reduce risk because it requires us to get evidence:

• Assume cars are coming, so we look both ways before pulling into traffic
• Assume the communication wasn’t understood, so we confirm with the receiver what they heard
• Assume the medication may be wrong, so we verify before administering it
• Assume the phone may not be charging, so we look for the lightning bolt

When we assume things might not be good, the assumption now creates a reason to check. The assumption has not told us what is true. It has told us that we need to verify the situation.

It's bad to assume things are good.

It's good to assume things are bad.

A Best Practice Built on Assumptions: Be Prepared

When you’re hiking in the woods, assuming that things could go wrong—and being ready if they do—can save your life. That’s why the Boy Scout motto is “Be Prepared.” Organizations that prioritize safety and reliability take a similar approach. Racing organizations and teams like F1 and NASCAR are obsessive about preparation and checks. Cybersecurity groups and elite miliary units can seem almost paranoid about potential problems. The common thread is an unwillingness to assume that everything is fine simply because it seems OK.

Highly reliable organizations make assumptions. But their baseline assumption is not, “It’s probably fine.” It’s closer to, “It might be wrong.” That assumption requires a check, a verification, or some other deliberate step to establish the actual condition before proceeding. Instead of allowing an assumption to stand in for evidence, they use the assumption to create a reason to get evidence that things are good, correct, and safe.