Lesson 1: Recognising Assumptions - The Invisible Foundations of Thinking

Lesson Objectives

By the end of this lesson, you’ll be able to: - Identify hidden assumptions in your own thinking and in others’ arguments - Distinguish between reasonable and unreasonable assumptions - Apply techniques to uncover and test assumptions in everyday situations - Develop the habit of questioning assumptions before drawing conclusions

What Are Assumptions?

Let’s start with something we can all relate to. Have you ever had this experience? You send a text message to a friend, see those three dots indicating they’re typing a response, but then… nothing. The dots disappear, and no message arrives.

What happens in your mind? Perhaps: - “They’re angry with me.” - “They got distracted by something more important.” - “Their phone battery died.” - “They’re carefully crafting the perfect response.”

Each of these interpretations rests on an assumption—an unexamined belief we accept as true without evidence. Assumptions are the invisible foundations of our thinking, the unquestioned starting points that shape everything that follows.

The problem isn’t that we make assumptions—we have to, or we’d be paralysed by endless analysis. The problem is that we often don’t realise we’re making them.

Why Assumptions Matter

Unexamined assumptions can lead us astray in countless ways:

• Misunderstandings: “She didn’t compliment my presentation, so she must have hated it.” (Assuming silence equals disapproval)
• Poor decisions: “Everyone says this investment is a sure thing, so I’ll put all my savings into it.” (Assuming popular opinion equals truth)
• Unnecessary conflicts: “He’s a conservative/liberal, so he must believe X, Y, and Z.” (Assuming political labels perfectly predict specific beliefs)
• Missed opportunities: “I’m not good at maths, so there’s no point in applying for that job.” (Assuming past performance dictates future capabilities)

When we fail to recognise our assumptions, we limit our thinking and close ourselves off to alternative possibilities.

Types of Assumptions

Assumptions come in various forms:

1. Factual assumptions: Beliefs about what is true in the world
• “The economy will improve next year.”
• “Crime is increasing in my city.”
2. Value assumptions: Beliefs about what is important or worthwhile
• “Freedom is more important than security.”
• “It’s better to be honest than to spare someone’s feelings.”
3. Prescriptive assumptions: Beliefs about what should be done
• “The government should regulate this industry.”
• “People should prioritise their health over their careers.”
4. Causal assumptions: Beliefs about what causes what
• “Violent video games lead to aggressive behaviour.”
• “Raising the minimum wage causes inflation.”

[Suggested graphic: A diagram showing these four types of assumptions with simple examples of each, perhaps illustrated as different layers of a foundation supporting a house of cards, suggesting how assumptions support our conclusions but can be unstable.]

How to Recognise Assumptions

Spotting assumptions—especially your own—takes practice. Here are some techniques to help:

1. Look for “Gap Words”

Words like “obviously,” “clearly,” “naturally,” “of course,” and “everyone knows” often signal an unstated assumption. When you hear these words, ask: “What’s being taken for granted here?”

2. Identify the Conclusion, Then Work Backwards

If someone (or you) has reached a conclusion, ask: “What would have to be true for this conclusion to make sense?” Those necessary conditions are often unstated assumptions.

3. Consider the Opposite

Ask yourself: “What if the opposite were true?” This can help reveal assumptions you didn’t realise you were making.

4. Use the “Five Whys” Technique

When you encounter a claim or belief, ask “why?” Then ask “why?” again to the answer, and so on, five times. This often reveals underlying assumptions.

5. Watch for Emotional Reactions

Strong emotional reactions often signal that an assumption is being challenged. If you feel defensive, angry, or dismissive about an idea, ask yourself: “What assumption of mine is being threatened?”

Reasonable vs. Unreasonable Assumptions

Not all assumptions are bad. Some are reasonable based on available evidence and experience. The key is distinguishing between:

Reasonable assumptions: - Based on reliable evidence or consistent past experience - Acknowledged as assumptions rather than certainties - Open to revision when new information emerges - Necessary for practical functioning

Unreasonable assumptions: - Based on limited, biased, or outdated information - Treated as unquestionable facts - Resistant to revision despite contradictory evidence - More extreme or absolute than warranted

Practical Exercise: Assumption Hunting

Let’s practice identifying assumptions in everyday statements:

1. “We need to cut taxes to stimulate economic growth.”
• Assumption: Lower taxes lead to economic growth
• Assumption: Economic growth should be prioritised over other goals
• Assumption: Current tax rates are high enough to be worth cutting
2. “You shouldn’t eat after 8 PM if you want to lose weight.”
• Assumption: The timing of food consumption significantly affects weight
• Assumption: The listener wants to lose weight
• Assumption: There are no exceptions to this rule based on individual circumstances
3. “Young people today don’t understand the value of hard work.”
• Assumption: Young people work less hard than previous generations
• Assumption: The speaker has accurate knowledge about young people’s work ethic
• Assumption: Hard work is defined the same way across generations

For each statement, ask yourself: Are these assumptions reasonable? What evidence supports or challenges them?

Real-World Application: News Media

News headlines and articles are filled with assumptions. Next time you read the news, try to identify:

• What facts are presented vs. what assumptions are made
• Whether sources are named and credible
• What alternative explanations might exist for the same events
• What information might be missing that would change your interpretation

Remember, good critical thinkers don’t reject all news as “fake”—they develop the skills to separate fact from assumption and evaluate information thoughtfully.

Managing Your Own Assumptions

Recognising assumptions isn’t just about analysing others’ arguments—it’s also about understanding your own thinking. Try these practices:

1. Keep an assumption journal: When making important decisions, write down your key assumptions and evaluate them.
2. Seek diverse perspectives: Deliberately expose yourself to viewpoints that challenge your assumptions.
3. Practice intellectual humility: Get comfortable saying “I might be wrong about this” or “I’m assuming X, but I should verify that.”
4. Distinguish between observations and interpretations: “My boss didn’t smile at me today” is an observation; “My boss is upset with me” is an interpretation based on assumptions.

Conclusion

Assumptions aren’t inherently good or bad—they’re simply a necessary part of how humans think. The goal isn’t to eliminate assumptions but to become aware of them, evaluate them critically, and revise them when necessary.

By developing the habit of recognising assumptions—in media, in others’ arguments, and especially in your own thinking—you’re taking the first crucial step toward becoming a more critical thinker.

In our next lesson, we’ll build on this foundation by exploring how to evaluate evidence and determine what information is reliable in a world full of competing claims.

[Suggested graphic: A before/after illustration showing a person initially accepting information at face value, then the same person pausing to identify and question assumptions before forming a conclusion.]

Next Up: Lesson 2 - Evaluating Evidence: Separating Fact from Fiction