The + and - Symbols: Simple Enough for Elementary Students, Yet the World's Most Confusing Concept
Let me talk about the most challenging concept in the world—at least for me. It’s so simple that even elementary school students understand it. But believe me, it gets you when you least expect it. I’m talking about... + and -. And yes, there’s a twist. Actually, there’s a twist to the twist—so buckle up. In my systems thinking lectures, I typically explain that when cause and effect move in the same direction, we use the + symbol and refer to it as a positive causal relationship. When they move in opposite directions, we use the - symbol and call it a negative causal relationship. I always emphasize firmly that "positive" and "negative" here are purely mathematical concepts—they have nothing to do with good or bad. Elementary School Level For example, when the birth rate increases, the total population also increases. Since both birth rates and population changes move in the same direction, we write: Births → Population (+) Conversely, when the death rate incr...