Southern New Hampshire University
PHL-111 Introduction to Critical Thinking
Module Four Overview
Module Four Learning Objectives
By the end of this module, you will meet these learning objectives:
Identify bias in a resource and in yourself
Assess the credibility of an argument by looking at assumptions and bias
Describe how your own bias influenced a decision
Module Four At A Glance
1. Complete the assigned textbook reading.
2. Review the module reading and resources.
3. Post your initial response to the discussion prompt.
4. Respond to at least two of your peers in the discussion.
5. Complete the journal activity.
Assumptions and Bias
In the last module, we learned how to assess the relative strengths and weaknesses of an
argument. We explored factors that make supporting premises for a conclusion more or less
effective. We then began analyzing essays and arguments in terms of the relationship between
premises and conclusions.
In this module, we build upon this skill by considering ways subjective influences, unchallenged
assumptions, and biases influence how we reason and formulate arguments. In doing so, we
examine how factors like emotions, cognitive-perceptual bias, beliefs, and prior experiences
shape the way we evaluate evidence and perceive its importance. These factors are often
consolidated in assumptions that we might treat as if they were factual. Some assumptions are
warranted (e.g., the sun will rise tomorrow, and the boss is usually available Monday mornings
around nine), and some are unwarranted (e.g., the earth is flat, and the boss is not open to my
ideas because he is not of my race). Discriminating between warranted assumptions and
unwarranted assumptions is essential, especially because unwarranted assumptions often harden
into biases or spring from pre-existing biases.
Although some people have lately softened the definition of bias into being mere preference, bias
is never a good thing. It represents hardened prejudices that act as a distorting lens, preventing a
clear view of people and events. Such prejudices are treated as factual when they are not. People
will often defend their biases and mount considerable resistance to any challenges to their biases.
This module asks us to examine how these factors shape how we select our sources of
information and how we assess their significance. Finally, we reflect on the importance of
becoming self-aware about our own bias and how it influences our ability to reason responsibly.
We often talk about arguments as though they have to be absolutely free of subjective influences,
assumptions, and personal biases in order to be legitimate, but this is probably impossible, and
possibly undesirable. As human beings whose intellectual purview is restricted (as well as
enhanced) by the subjective and contextual circumstances of our personality, perception, and
culture, we necessarily think within the parameters that these circumstances set for us. A critical
thinker learns how to spot assumptions and biases and handle them rationally.
We also want to become aware of these factors—and how they influence our thought processes
and reasoning—when we assess the relative strengths and weaknesses of arguments that we both
make and encounter. If we are not aware in this way, our subjective influences, assumptions, and
biases can become hindrances to accurate perception, clear thinking, and effective arguing. Bias
in thinking occurs when subjective, pre-established cognitive, perceptual, or social perspectives
shape the way we evaluate information and construct arguments (Diestler, 2012). Social biases
like conformism and unquestioned cultural beliefs make us devalue or overvalue certain beliefs
and practices without reflection and, most importantly, without justification (e.g., “we all know
that way of life is just wrong; it’s obvious”). Cognitive errors can distort the perceptions on
which we base our judgments without our even knowing it (e.g., “everyone else before me
played that number in the lottery and lost, so I knew that my chances of winning if I bet on it
would be better”). And of course, emotional influences often blind us to facts and evidence that
should be obvious (e.g., the wise old truism “love is blind” is based on an experience that almost
everyone has fallen victim to at least once in their lives). Recognizing subjective influences in
our own and other’s thinking is thus essential to reasoning and to assessing arguments.
This module will focus on two ways of dealing with unwarranted assumptions and biases. First,
we will look again at the power of counterarguments, this time to highlight its role in softening
bias and undermining unwarranted assumptions.
Secondly, we will reflect on personal experiences in which our own bias or someone else’s bias
has shaped our reasoning and actions. We will explore this in a short journal assignment about
how these kinds of bias affected our thinking and behavior in the past, and what we might be
able to do to change it.
You will also complete a discussion topic about possible biases (if any) in your essay choice for
the final project and to what extent (if any) these may influence the reliability of the essay.
References
Diestler, S. (2012). Becoming a critical thinker (6th ed.). Pearson.
