A few months ago, I found a YouTube video titled “How Logical Are You? (Psychology of Reasoning).” The narrator presents four cards, A, K, 2, and 7, as well as a rule: “If a card has a vowel on one side, it must have an even number on the other.” The narrator then gives the challenge, “Which card(s) must be turned over to determine whether or not the rule has been followed?” Give it a try yourself. The answer is hidden below.
You flip the A and the 7. A is a vowel, so it must have an even number on the back. A lot of people think you have to flip 2, but the rule does not prevent consonant-vowel pairs. If you find the 7 has a vowel on the other side, though, the rule is broken. In logical terms, the rule is a condition: “if A, then 2.” This is not the same thing as its converse, “if 2, then A,” nor its inverse, “if not A, then not 2.” A condition is, however, identical to its contrapositive. “If A, then 2” is logically equivalent to “if not 2, then not A.” So to test if the rule is followed, you have to check cards A and “not 2” a.k.a 7.
In the comments, people were saying things like, “I got the answer wrong because the instructions weren’t clear.” Nonsense! The rule is simple, and clear as crystal in its detail. Not wanting to have to face his own illogical thinking, the commenter tried to shift the blame to the rules of the game.
I also found a video of Neil deGrasse Tyson giving a speech about ordinary phrases that people say, but that are wrong. For the statement, “days get longer in the summer and shorter in the winter,” Neil explained enthusiastically how if the shortest day of the year is the first day of winter, then the days can only get longer, and if the longest day of the year is the first day of summer, the subsequent days can only get shorter.
In the comments, though, people said things like, “that one about the seasons and the days isn’t wrong.” Below that, someone would say, “yes it is. If you read the sentence for what it says, it’s claiming that in the summer, every day is longer than the one before it.” And below that, the first person would reply, “that’s just semantics. When someone says ‘days get longer in the summer and shorter in the winter,’ it’s implied to mean the days are longer in the summer than in the winter, like everyone knows.”
This person is appealing to common sense to override the sloppiness in wording. What they don’t realize is that there is no such thing as common knowledge. Everyone learned about the length of the days in summer and winter from somewhere, and some people learn it for the first time from people who word it wrong. These people then go about their lives with an inaccurate picture of the world in their heads, and then repeat the false knowledge to their children, family, and friends. One or two words can make a huge difference.
It may seem like I’m saying people are stupid. Not at all. The central aim of a writer is to evoke feelings and direct the thoughts of the readers. To do this well, the writer needs to understand how the readers think. For most people, intuition will get them through their day just fine, so they don’t have much practice thinking in terms of logic and details. As an analytical thinker, I have to keep in mind that most of the people who read my stories will be intuitive thinkers, and I should write so that both types of people will understand and enjoy it.
Maybe you’re not a scientist. Maybe you already think like an average person. In that case, writing for intuitive thinkers will come naturally to you, and you might instead have to work at understanding analytical thinkers. Novel writing is an exercise in empathy, and no matter where you’re coming from, it’s always a good idea to try to understand someone who thinks in a different way from you.