Why Assumptions Should Be Avoided Unless Productive

Introduction: What Are Assumptions?

An assumption is an opinion or belief often held without evidence or proof to support it. Assumptions tend to be based on preconceived ideas about certain people, places, things, or events. A person forms an opinion — consciously or unconsciously — without actually having all the information that a critically thinking individual would require before formulating a judgment on the matter. There are many types of assumptions, and they all impact people and their lives in different ways. This paper describes the various types of assumptions, how they affect us, and why we should generally avoid making them.

There are three main types of assumptions: (1) paradigmatic, (2) prescriptive, and (3) casual. Paradigmatic assumptions are the most difficult to identify, usually because a person does not know how to recognize them. These are assumptions that are ingrained in our worldviews — they inform the frameworks by which a person judges. They can become ingrained in a person's thinking based on teachings or on ideology that the individual has embraced. Paradigmatic assumptions are typically beliefs that a person holds as true, factual, or self-evident.

The Three Primary Types of Assumptions

Prescriptive assumptions are those that pertain to whether something is good or bad, or what should or should not happen. They are based on values regarding cause-and-effect notions. For instance, a prescriptive assumption might hold that nature rather than nurture determines a person's personality — that if one's biological stock is of good genetic material, one should have a good personality. This view does not entertain the possibility that such thinking might be too narrow or constrictive.

Casual assumptions tend to be based on prior personal experiences and are often the easiest to identify. One might have a bad experience at a restaurant and then assume that every future visit will be similarly unpleasant, avoiding that restaurant altogether. This is a straightforward example of a casual assumption (Identifying and Validating Assumptions).

Assumptions often go unrecognized, which is why they can be so problematic. People make decisions without realizing they are assuming something that may or may not be true. Unrecognized assumptions can negatively impact the effectiveness of one's decision-making (Spacey).

How Assumptions Go Wrong: Unrecognized, Unstated, and Unquestioned

Assumptions can also go unstated. For instance, one person on a team might assume that a colleague already knows what they know. Without communicating this, the assumption stands — and it may turn out that the other person had no such knowledge. Unstated assumptions typically lead to setbacks and are one of the primary reasons why clear communication is so strongly encouraged on teams (Turk, Robert, and Rumpe).

Assumptions that go unquestioned are equally dangerous, as they can lead to groupthink. Beliefs should be stated openly so that others are aware of them, and they should be expressed in a way that invites scrutiny. A culture in which assumptions are not challenged is one that invites serious errors. Groupthink is widely cited as a key factor in the Challenger space shuttle disaster: no one challenged the assumptions being made about the shuttle's safety (Esser and Lindoerfer).