What would a fantasy medieval world be like if all the humans no longer have the emotion and feeling of love? There's always romantic crap going on in some fantasy books. So then I thought what if the characters don't give a poop anymore. Like a jealous wizard or witch wished it all the love to go away forever because he or she is lonely and thinks love just make people miserable. Would families no longer exist and stop reproducing? And would they stop taking care of their children? What would you think would happen?
Other animals can't be said to truly love, but reproduce and form societal structures. Trees don't have emotions (maybe) and reproduce and form structures and, in some cases, relationships.
The strong emphasis on romantic relationships is actually a modern thing superimposed on stories supposedly based in the medieval era, real or fantasy. At the time, most marriages of the upper classes were arranged by families. Attempting to court a girl without the parent's permission could start a minor war. The higher the person's rank, the more political the marriage would be. Therefore, if you want to write a story where there is very little romance, go right ahead. You will be actually be more in line with historical reality.
Love is very physiological, it is a fundamental law of attraction, in a way. Even elementary particles interact and have affinity for one another (or repulsion, or indifference). Humans are social animals. Absence of love would most likely lead to a complete breakdown of the fabric of society as we know it. No more looking after children or one another, sharing, cooperating, compassion, and perhaps on a purely physical level, love is actually just a release of certain neurotransmitters, which are responsible for a lot more functions than just 'feeling love'. I imagine inability to feel love at all might lead to bodily dysfunction, illness and premature death. Most of all, self-love is also love, and it is fundamental to our survival, our love of being comfortable, nurtured, nourished, safe, clean, all that stems from being able to love. That too would be affected. Alternatively, you could have people's empathy ruined by magic, so it becomes 'every man for himself' kind of society and everyone in it a raging narcissist and a psychopath. Such a place would be very violent and dysfunctional but might make an interesting premise for a story.
I think humans would just stop. If you've ever seen some of those orphanages over in Russia?, the kids are crippled, shriveled and catatonic because no one held them as a baby and usually it's a state they can't return from.
You could do pretty much anything you like here, if you can make it seem reasonably plausible. Children would be seen as an investment for the future, someone to look after you in your old age, so I don't see much of an issue here. People would still cooperate on the principle of what goes around comes around so this would actually be self interest. The absence of love might also extend to the absence of personal preference. The ugly would be just as appealing as the beautiful. Sweet foods no more desirable than bland or bitter. Children would eat sprouts! Sprouts would become popular and replace every other kind of food. The sprout event horizon would be reached. It would become economically impossible to grow anything other than sprouts. But since wizards don't like sprouts they reverse the magic and . . .
I think that love is an evolutionary survival characteristic, and that any species that lost it would slowly cease to exist. The idea that "this howling, stinking creature for which I have to work day and night will carry on my genes and might care for me in my old age" wouldn't be enough to keep you from just smothering the thing some night, without love. (That does mean, yes, that I think that animals feel a variant of love.)
