We are always advised by petshops to get dwarf hamsters in a pair because 'they are social animals. They will get lonely'. But that is only half of the story.
Though dwarf hamsters do live in a community, they are pretty quarrelsome, and it could be better to let the hamster live alone than with a companion it can't get along with. It all depends on the hamsters' personalities. Two dominant hamsters would certainly fight with gory consequences. So we are lucky that the TwinSqueaks get along so well. Mind you, there is always plenty of squabbling and squeaking at night, mainly over food. Since they are happy with each other in every other way, we let them live together still.