Illogical Reasoning
Illogical reasoning is when we impulsively draw a conclusion or argue that something is true based on unproven assumptions (6). Before we look at an example of illogical reasoning, let’s go over some important definitions in scientific research (8).
​
Correlation: is when two variables change together. When there is a positive correlation that means they both increase or decrease together. When there is a negative correlation that means one increases and the other decreases. But that doesn’t mean they are dependent on each other.​
So we say x and y change at the same time
Causation: when one variable elicits a change in another. So we say that x changes y.
Let’s look at a hypothetical scenario. For example, if there was a data set that shows a positive correlation between people who exercise more and skin cancer, does this mean that people who exercise more tend to be the people who get skin cancer? You may come to the conclusion that exercise causes cancer (8). But this is not the case and is a result of illogical reasoning. In reality, this correlation between exercise and skin cancer exists because people who live in places with a lot of sunlight year round are more active and are outside more in their daily lives than people who live in places that don’t get a lot of sunlight year round (8). So, we cannot make the assumption that correlation equals causation.
In our day-to-day lives, it is easy to use these types of reasoning. We subconsciously make assumptions and draw conclusions to make sense of problems we face or observations we make about our surroundings.
In scientific research, we cannot use these types of reasoning to determine truths about our world. Only when further experimentation through the scientific method is done can an abductive or inductive conclusion be deemed as true. However, through inductive and abductive reasoning, scientists can make predictions or hypotheses which can be further tested.
At the start of the 19th century, Uranus was observed to not follow the orbit that is predicted by Newton’s theory of universal gravitation. The possibilities were either Newton’s theory was wrong or there was another planet. A couple of astronomers suggested that there was an 8th planet, but this was not based on any other information other than Uranus’ orbit. This eventually led to Neptune’s discovery based on mathematical calculations to estimate its specific location in the sky and observation with a telescope (10, 11).
Did you know...
About Us
Science for Everyone is a Canadian Nonprofit Organization that provides educational resources to help raise the level of scientific literacy in the general population.