I wonder if the people who expect their partners to “just know” are confusing successful non-verbal communication with telepathy.
I would guess typical mind fallacy, or illusion of transparency. Either they believe their signals are obvious, or they believe that any (sane) person would make the same guess in that specific situation. Or a combination thereof, i.e. that any (sane) person would only see two or three possible choices in that specific situation, and the signals are sufficient to differentiate among them.
Another interesting question would be whether these people are able to see the situation from both sides. Like, they can be angry at their partner for not reading their mind successfully, but do they believe they read the partner’s mind successfully? Maybe they don’t even realize that there is the other side, too. Or maybe they blame the partner for communication failures in both directions. (“They should know what I think about.” “They shouldn’t think such crazy things.”) On the other hand, maybe the partner really is predictable. Or the partner communicates their thoughts explicitly, so one way the communication is clear, and the person simply does not realize that the clearness of communication is caused by the explicitness. (Or maybe they don’t believe in symetry. Maybe they believe that being explicit is e.g. gender-specific, so it’s okay that the partner is explicit, and it’s okay that they aren’t. Or perhaps that you should be explicit about some things, but not about other things.)
I would guess typical mind fallacy, or illusion of transparency. Either they believe their signals are obvious, or they believe that any (sane) person would make the same guess in that specific situation. Or a combination thereof, i.e. that any (sane) person would only see two or three possible choices in that specific situation, and the signals are sufficient to differentiate among them.
Another interesting question would be whether these people are able to see the situation from both sides. Like, they can be angry at their partner for not reading their mind successfully, but do they believe they read the partner’s mind successfully? Maybe they don’t even realize that there is the other side, too. Or maybe they blame the partner for communication failures in both directions. (“They should know what I think about.” “They shouldn’t think such crazy things.”) On the other hand, maybe the partner really is predictable. Or the partner communicates their thoughts explicitly, so one way the communication is clear, and the person simply does not realize that the clearness of communication is caused by the explicitness. (Or maybe they don’t believe in symetry. Maybe they believe that being explicit is e.g. gender-specific, so it’s okay that the partner is explicit, and it’s okay that they aren’t. Or perhaps that you should be explicit about some things, but not about other things.)