When building a well populated world, social norms are the genetic makeup. Issues like religion, geography and economy may be the ultimate basis for the world, but social norms are what your audience will spend 90 percent of the time with. Social norms are both easy, and surprisingly difficult to create. For some reason, your audience will accept floating mountains and magic gems without question, but if everyone speaks in rhyme, or no one wears clothes, “That makes no sense!” It’s your job as a world builder to make it “make sense”.

small talk
As covered previously in the religion post, much of what you say is influenced by your culture. In most European nations, it’s genuinely confusing to be asked “how are you” on the street. In the US we accept it as a simple greeting, elsewhere it’s seen as a serious question. Why is that? Don’t be afraid to have people in your world talk about more than the weather. On the other hand, the weather may be a dangerous topic.

large talk
Is talking about politics, sexuality, religion, etc. acceptable or not in your world? Why or why not? If your world isn’t related to ours in any way, let the large talk rely on something else. Maybe people talk about the growing threat in the west. They’re not immediately worried about it, but it’s obvious to your audience that something major may occur later on in your story. Don’t get too large however. No one wants to spend 5 books hearing about the main character’s latent ennui.

in the home
You might not think of how you talk to your family as a “social norm”, but much of it is based on media you’ve observed, or the culture you’ve been raised in. Something as simple as saying “good night” or “I love you” is certainly a social norm. Is there a deference to elders? Maybe a deference to the younger members? It’s important to flesh out familial normalities since that’s an area that is oven neglected, or misunderstood, even in real life. Many stories begin and end with the family, focus on it.

in the street
“On your way man”, “only in accordance to you, lord”. That sounds fairly odd or contrived, but similar conversational patterns have existed on our planet. As opposed to social norms that occur in private, social norms occurring in public are probably richer in opportunity to express religion, history and economy. They are often more rigid, and based on some, at least subconscious societal agreement. I suggest you go creative then shape your creation into believability.

in the end
I put forward the opinion that social norms are the most important part of world building. We’ve all imagined strange geography, strange religion, strange occupations, but how many of us sit around thinking about new way to say “hello”? It should be important to you. We’re not building “Europe in space” or “the Vietnam War in 10,000 BC” we’re building another world.