2.1 The Brain Is an Inference Machine

By the end of this section, you will be able to:

• Describe the role of emotion in thought.
• Explain how cognitive systems produce inferences without conscious thought.

One of the first steps to becoming a more critical and reflective thinker is to understand how and why you are prone to making mistakes in thinking. These mistakes are not the result of a lack of intelligence but are a function of the way our minds work and how they naturally lead us astray.

From a biological perspective, we have been shaped by hundreds of thousands of years of evolution, which have primed our brains to become extremely effective inference machines. An inference is the mental process that allows us to draw conclusions from evidence. While we tend to think of inference as a deliberative and conscious process, we infer all kinds of things unconsciously, effortlessly, and immediately; in fact, most of sense perception is a kind of inference. Inference making has been crucial to human survival, but our conclusions are not always correct. By becoming aware of how our brains function to ward off threats and provide us with “cognitive ease,” or a feeling of well-being and comfort, we can begin to correct for and guard against faulty thinking.