Getting emotional with sci-fi

"My heart is full of X."

  

So we can easily imagine an alien, or a mutant with different abilities, different physiologies: four heads or tentacles for arms or the ability to walk through walls, or even an intelligent shade of blue (I think Douglas Adams came up with that one). But what if an alien or mutant or even just a different earthly species were equipped with an entirely different set of emotions, beyond hate, love, fear, doubt and chagrin. Emotions x, y, and z, a whole alien array, so different from our experience that they in no way correspond to anything in our ken?

We could still witness the physical manifestations of their emotions, like tears or blushing or the spraying of ink, but have no idea of their predicates. Would we be able to divide their emotions into positive and negative reflexes, or would that only mean positive or negative outcomes for ourselves if we responded correctly? What would be the key to unlock their "hearts?" We have a name for every shade of human emotion, yet we can barely even read the hearts of our own species. Probing might turn out to be be a highly decorous form of salutation.

Oh, Lord, please don't
let me be misunderstood

If we throw rocks at an alien, and an alien responds by hugging us, could we therefore assume that having rocks thrown at it is a positive experience for E.T.? And we can interpret their pelting us with rocks in turn as a positive sign? Or is its hug meant as a retaliatory response? Or is the alien simply modeling correct behavior in the hope that we will imitate it and leave off with the rock-throwing? (And how would it feel about being be referred to as an "it?" Does it have unimagined pronouns?) Or is it displaying x emotion? 

We may be able to elicit what we consider positive behavior from an alien or a mutant (provided their emotions are consistent and discrete, a very big if, considering our own emotional variability and opaqueness) but we could never know the impetus for that behavior. Are we perhaps aware of only a small sliver of the emotional spectrum? The aliens might even be able to teach us to access emotions hitherto unknown within ourselves. Perhaps those emotions are the key to inner peace that Tibetan lamas have been trying for centuries to tap into. Is there a numinous emotion waiting to flower?

We can only see a small range if the electromagnetic spectrum. Only hear within a small frequency range. Our ability to smell is shamed by every other mammal on this planet. Why should we think we have a grasp of all available emotions? All our fictional aliens display fundamentally human emotions. Even  the "emotionless" Vulcans merely demonstrate stoicism taken to its (ahem) logical conclusion. Science fiction has done a pretty good job of speculating on how we might establish communication with an alien intelligence. But that is only sense, not sensibility.

 I may be wrong. Sci-fi literature may be chock-a-block with examples of this conundrum. Has anyone come across one of them? Let me know. And if not--well, I'm not a sci-fi writer, so I invite, nay challenge any writers reading this to take up the problem and solve for x.