True, and I don't mean to underplay the difficulty of that style of learning. In particular, it seems important that our emotion-reading is reflexive - we learn to map other people's expressions to our emotions, and it's not clear how similar a learning process without some reference class of emotions.

(We have a decent example in autism of how emotion without instinctive mirroring plays out in learning emotional signals. The associations are learned consciously, which works out alright. But I'm not sure there's any precedent for people who have mirroring but nonexistent emotions. Is there something like abulia for lack of emotion? ...is it abulia?)

I'm going to stand by the original statement, though. We have proof that this sort of learning without a backing theory can be done, and no real evidence that having a general theory would make it easier to actually learn the specific associations needed to make predictions. To steal an example from the article: knowing whether the six-emotion model is right or wrong doesn't automatically help us recognize a clenched fist as threat or celebration, and fretting about the impact of psych textbooks on AI without proposing an actual connection isn't particularly compelling.

Yes, and children experience emotions before they learn to reason or use language, so they have a personal basis to work from when learning to reason about the emotions of others.

"Empathy" is the name of the reasoning process by which children analyze the experience of their own emotions and behaviors, to draw inferences about the emotional state of others based on observing their behaviors.

But long before that, they are reacting emotionally to the behaviors of others. For example, you can scare a baby.

The scale of the learning is interesting in itself. From a few months, to years old, to all the way to preteens, emotions are constantly being reevaluated and developing new ones as well.