This is generally how “folksy wisdom” keeps getting passed down generation to generation until it ends up in a farmer’s almanac.
It sounds reasonable, and so gets taken for true even though it has no (that I’m aware) actual scientific evidence to back it up.
It’s a causation fallacy. ie) correlation does not necessarily equal causation. Just because two things are statistically correlated, doesn’t mean that one causes the other.
It’s like if I were to say “Hey, The midwest has higher instances of heart disease. Therefore moving to the the midwest will give you heart disease.” It’s not true.
The two things are correlated, certainly, in that the mid-west folks probably for the most part has a much fattier diet, and are less likely to engage in healthier eating habits. But just the simple act of being in the midwest isn’t a cause of heart disease.
Correlation does not equal Causation. Print it on a card and keep it in your pocket please. People not grasping that concept and passing off folksy anecdotes as “wisdom” has been the cause of too much suffering.