Many quite brilliant people do not know the difference between contempt and silence.
Take a basic situation; someone gives an instruction, or correction, or raises an issue and the person to whom they speak says nothing. Simple looks.
One with a high I.Q. will accept that the person who is silent is compliant.
The person with a high E.Q. might catch that this may be an indication of contempt.
Many intelligent people do not notice the difference between one who seems submissive and one who has contempt. In fact, it is likely they do not even imagine it.
When one holds contempt they can’t be bothered to argue, discuss, even speak. As the behaviour can be read as submissive, those who are not Emotionally Intelligent will be fooled.
Fooled by their own ego.