I have always been handicapped by the absence of an ability that people seem to take for granted. Like, if I am told 'Drop in any time', I take that as an invitation; people seem to understand it as a meaningless courtesy. I take words literally for what they mean. People seem to read in different meanings into the same words depending on when it is said; who is saying it; what their tone of voice is and so on and so forth. Never learnt all that, never will and now I have given up on understanding how to parse it and, even, why people do it.
So, yeah, when Tiru goes one step further and says this...
Kooraamai nokkak kuripparivaan enyandrum maaraaneer vaiyak kani - Tirukkural
He who, without words, understands with a look is a gem of this world girded by undrying seas - Loose Translation
I don't think that Tiru meant that such a person is but dross in a desert world like Dune. It's just that he needed to make a decent couplet of it and, so, rounded it off with that 'undrying seas'. So, I do not even have that solace. I mean, I cannot understand WITH words, so what are the odds that I'm going to understand with just a look at the other guy's face? So, yeah, no priceless gem, me!
I CAN understand how I might like that in a subordinate. I mean, there are times when you CANNOT say what you want. Like, you got this boring chap who's droning on and on; who you cannot unceremoniously chuck out; and then your assistant pops in saying that your boss wants you, just so you can give this bore a bum's rush without it appearing so...THAT's a benefit of having a guy who can understand a situation without your having to explain chapter and verse to him in single syllable words.
AND, perhaps, in Tiru's times, the King treasured a minister who could take a look at the frowning Queen's face and divine the cause of her anger AND find a way to redress the situation. (Yeah, yeah, any boss would like it but the Home Office concept does not give enough opportunities as the palace of yore did.) Given the almost congenital inability of men to understand their women, I can quite see how such a person would be counted as a Kohinoor among ministers.
The fact is that such a person will prove himself to be the most congenial of people and, thus, the most priceless. To be able to read the face to read the mood is to ensure that you do not speak the wrong words at the wrong time. That's not necessarily to be a lickspittle. It is to know WHEN to give the advice and how best to put it. The ability to know how the people around you are feeling is also the ability to be convincing because you will know how they are reacting to what is being said.
Alas! I'll be content to know what the words people say actually mean. Reading faces and tones and body postures...too much trouble!