There are a lot of experiments showing that wine experts are very unreliable: by serving them the same wine in 2 different bottles (cheap and expensive), by add

There are a lot of experiments showing that wine experts are very unreliable: by serving them the same wine in 2 different bottles (cheap and expensive), by adding food colorant to white wines, etc. Daniel Kahneman describes some of them in "Thinking Fast and Slow". The same thing has been done with other fields dealing with vague and loosely-defined concepts: stock-picking, sports commentary, etc.