There’s a lot to be learnt from the romance genre when we’re thinking about writing emotion.
At the heart of it, the old cliché is one person meets another person, overcome obstacles while falling in love, and live happily ever after. I’m not saying that’s all romance novels are but let’s stick with the most basic plot for this argument. It’s the middle bit we’re most interested in, the bit where they fall in love. In some stories, this is love at first sight but let’s look at the journey where they meet and gradually fall in love because this is where showing emotion without telling appears most often. I don’t think I’ve read many plot lines where it is explicitly stated both characters are falling in love, it’s all shown by how they interact: the way they behave and the way they speak.
For instance, they may meet and dislike each other at first so at this point their conversation may be brief, frosty and impersonal. This will gradually change, jokes, compliments, and personal details may begin to slip into the conversation. By the end of it, they’re laughing and teasing and sharing secrets. In this way, the change in the way they speak to each other betrays the changing emotions of the characters without the writer explicitly stating ‘Adam is falling in love with Katrina’ or vice versa.
Another way this may be shown is through how they move around each other. People speak as much with their bodies as they do with their words and if two people stand far apart we may infer that either they don’t know each other or they don’t like each other. As their relationship changes, they move closer, their eye contact increases and their hands become more animated. By the end they stand or sit close together, sometimes leaning in closer, they touch, perhaps holding hands or to pick away some lint, and they can speak without speaking, by which I mean they read the expressions and body language of their partner. I haven’t forgotten the kissing but that’s not always transferable to other close relationships.
In this way, by using dialogue and physicality, you can portray the growing relationship between characters and therefore their emotional relationship as well. This doesn’t mean you can’t tell too but telling can make a story seem flat and, when overdone, can leave the reader unsatisfied because they haven’t had the space to make their own conclusions. When developing the emotional arcs of your characters it’s important to consider the balance of these two in editing. If you’re uncertain get someone to read your work them ask them what they think the emotional arc is and if they think there’s anything that needs adding or taking away to make it clearer or more satisfying.