Evaluating Casual Arguments

Read each causal argument below and notice its conclusion

Then, evaluate: how strong or weak is this argument? Is there good reason to believe the claim — or do you see any common causal confusion(s)? Could there be other, better explanations? Explain.

Tip: to get full credit, explain your thinking in detail! That’s more important than getting the “right” answer.

Common causal confusions, as described in the Module 14 videos

  1. Fallacies, e.g. appealing to ignorance, slippery slope fallacy, post hoc fallacy;
  2. Being misled by coincidence;
  3. Misidentifying relevant factors (i.e. the suggested cause is not truly relevant);
  4. Confusing cause and effect;
  5. Mishandling multiple factors (e.g. ignoring other relevant factors);
  6. Correlation is not always causation.


The majority of people who die are in bed at the time of their death. Clearly, being in bed increases a person’s risk of dying. Therefore, if I sleep on the sofa, I have a better chance of living longer.

You might say, “This argument is pretty weak. I think it confuses cause and effect because it doesn’t consider that many people who die are already sick or old; in other words, they don’t die because they are in bed, they are in bed because they’re dying. Besides, where you sleep is not relevant to how long you live. Your health, your genetics, your diet – these are things that can help you live longer, but not your bed.”

Your turn

  1. Ever since I started drinking herbal tea in the morning, my energy level has improved and I’m a lot calmer during the day. Herbal tea really works!
  2. I know for sure that black cats are a bad omen. The other day, my friend Dave and I were walking down the street and a black cat accidentally walked across the path in front of us. Ten minutes after that we both tripped on a rock and fell down.
  3. Why are crime rates so high, the economy so bad, and our children so prone to violence and bad behavior? These social problems have come – as they always have – from the lack of morals that is created when Americans turn away from religion. Our current problems started when prayer was banned from public schools. As God has slowly faded from public life, we have gotten deeper into the hole.
  4. Luke was feeling frustrated and negative about his chemistry class because all his quiz scores were D’s and F’s. He decided to change his attitude and think positively about the class: “I can do this!” he thought. The very next day, the professor returned a quiz, and Luke had gotten an A! Having a positive attitude really worked!
  5. Playing sports has a negative effect on intelligence. Studies show that college athletes have a significantly lower graduation rate than non-athletes.
  6. Marijuana is a gateway drug. Therefore, you shouldn’t smoke marijuana. If you do, you will move on to use cocaine. According to studies, children and teens who have used marijuana are 85 times more likely to use cocaine than those who have never used marijuana.