Gideon depicts a society so overcrowded that the bodies of the population are literally pressed up against the walls of the building just because they have no place else to go
...Inside one building, an important one where many people would be doing business. Obviously, the same isn't going on outdoors, on a world with actual open terrain and bodies of water.
People today live in conditions exactly as cramped as that. In a busy street, it's literally shoulder to shoulder. In a standard apartment in a really big city, it's easily twenty people living
in five square meters of floor space, not just wandering through it on their business.
you don't see a lot of that sort of behavior in sentient species
Forgetting for now that we only have one species to meet the specs...
...What behavior? Sex? We certainly do. Out of those twenty people living in the five square meters, any two might be having sex, with the other eighteen politely ignoring the noises. Going out is an option only with terrain and weather permitting, and in a big city, or in a rural setting in winter, that's not often.