[samtho]

The problem with the phrase “No evidence” outside of a scientific context is that it sounds like it’s dodging the question, when, as you pointed out, it just means we don’t have data to support that relationship. The other way this is used is to try to “prove” a negative by communicating that we cannot establish a link, and may be accompanied by the expert stating there is evidence for the opposite case. Text bites rarely have context other than this “no evidence” statement.

For a layperson, they feel like they are having the wool pulled over their eyes and are not given a truthful answer. For example:

    Interviewer: Can you say for certain that X causes Y?
    Scientist: We have no evidence that X causes Y.
    Interviewer: But can you say for certain that Y is NOT caused by X?
    Scientist: There is no evidence of that relationship.

The scientist is trying to choose their words carefully because they are operating on the principle of only communicating what the data is telling us. The interviewer wants a clear, definitive answer. Both parties become frustrated.

I do agree with the article that this is poor communication because the scientist sounds like a lawyer and is hiding something rather than stating the facts of the situation. I’m sure there are better ways to communicate this that communicate either “we don’t know yet” and “we do not believe there is a link” instead this line.

Side note: another related and interesting distinction is the difference between unproven and disproven. If you saw a headline that a major hypothesis was “unproven”, it means only that there is no data to support it. Disproven is what the layman often thinks this means which is actively finding evidence to the contrary.