Activity:
Distinguishing Inferences and Assumptions
It is important to distinguish between an inference and an assump-
tion. These two parts of thinking are easily confused with
one another. An inference is a step of the mind, by which one
concludes that something is true based on something else being
true, or appearing true. Inferences can be justified or unjustified.
All inferences are based on assumptions, beliefs we take for granted.
Justifiable assumptions lead to reasonable inferences. Assumptions
often operate at the unconscious level. When we uncover our
assumptions, we often find the roots of prejudice, stereotyping,
bias, and other forms of irrational thinking.

Consider these examples:
Situation: Your nation is in a conflict with another nation.
Inference: Your nation is justified in this conflict.
Assumption: Your nation is always justified in its conflicts with other nations.
Situation: I got an “A” in my composition class.
Inference: That proves I am a good writer.
Assumption: All students who get an “A” in composition class are good writers.
Situation: Your nation is in a conflict with another nation.
Inference: Your nation is justified in this conflict.
Assumption: Your nation is always justified in its conflicts with other nations.
Situation: I got an “A” in my composition class.
Inference: That proves I am a good writer.
Assumption: All students who get an “A” in composition class are good writers.
Consider the following method for identifying inferences and
assumptions in one’s thinking. We first determine what one might
infer (either rationally or irrationally) in a situation. We then figure out
the generalization that led to that inference. This is the assumption.
Information (Situation)
Possible Inference One Might Make
Assumption Leading to the Inference
1. You have difficulty learning in class.
1. It is the teacher’s fault
1. Whenever students have difficulty learning, it is the teacher’s fault.
2. You notice a man reading a book by Karl Marx.
2. The man must be a communist.
2. All people who read books by Karl Marx are communists.
3. You see a child crying next to her mother in the grocery store.
3. The mother has refused to get the child something she wants.
3. Whenever a child is crying next to her mother in the grocery store, the mother has refused to give the child something she wants.
4. You see a man sitting on a curb with a paper bag in his hand.
4. The man must be a bum.
4. All men sitting on curbs with paper bags in their hands are bums.
Now think up your own situations. Formulate inferences that might follow from those
situations. Then figure out the assumption that led to each inference.