Causation logic

Julia L

I'm looking at PT44-S2-Q20 and the explanation for why A) and D) are wrong raised a question for me. In the explanation, it sounds to me that just because A causes B, A can happen sometimes without B happening.

JY gives the example that smoking causes lung cancer. But just because you smoke doesn't mean that you get lung cancer. Normally if B is a necessary condition of A, then A always guarantees B. But from what he's saying it sounds like for a causal relationship, B does not always have to happen when A happens? Is it because there is a distinction between "tends to cause" and "cause" ?

Thanks!
Julia

c.janson35

Hey Julia!

The issue here is that conditionality and causality are not the same, and so imputing sufficiency onto a causal relationship is incorrect. There is a big difference between saying "smoking causes lung cancer" and "if you smoke, you will get cancer," which is why you shouldn't diagram a causal relationship with the standard conditional arrow. The two ideas are connected in causal relationships, but the presence of one variable does not have to guarantee the presence of the other, as JY explained with the smoking example.

Hope this helps!

Julia L

thank you @c.janson35 ! putting it into if/then terms helps clarify the distinction.