"That is not always the case in all societies."
Translation:Ce n'est pas toujours le cas dans toutes les sociétés.
You should not have to guess because the meaning should guide you to each use of "les" or "des".
"All societies" or "all the societies" translates to "toutes les sociétés".
The adjective "tout, toute, tous, toutes" by its very meaning can naturally introduce a whole mass or category; and the article for such meanings is "le, la, les":
- tout le monde = everybody
- toute la journée = (for/during) the whole day
- tous les jours = every day
- toutes les sociétés = all (the) societies
A more literary alternative can be found: "toute société", which often means the same thing, but in singular and without an article.