I personally never recommend keeping them together if you have the option. They really receive no benefits from it, and rather, can become stressed and sickly. I personally think it is a bit selfish to force to animals together, and then have one of them killed. It's a horrific sight- one I wouldn't wish upon anyone. I personally have never owned groups of dwarf hamsters, but throughout my childhood, many of my friends had. I also volunteer at groups that have pairs, and Id say about 75% of the time, it ended very badly. It's a shame because it really is such a preventable tragedy. If you ask almost any owner of pairs, they can tell you it really isn't such a great thing. Most owners end up worrying every night, whether or not one of their hams will still be there in the morning. It's just a preventable tragedy, and honestly, it isn't all that pricey to go out and buy a seperate cage
Or just split a detolf! There are so many other options out there, so there really isn't a need for pairs aside from breeders
Now to get to the more scientific side of things...
Hamsters in the wild do not live in groups/pairs. They're actually mainly solitary creatures, only coming together, and staying together for breeding purposes. You're not likely to find a group of dwarf hamsters in the wild, simply because they aren't social, and tend to stick to themselves. However, they also will not usually immediately kill another hamster in their territories. Hence is why people have perpetuated the myth that they're social creatures, which simply is not true! There is little good literature on pairs, but the only scholarly articles I've found, would indicate that there are very few cases where hamsters will live in groups aside from breeding. There have been a few studies completed that assessed them living together. What they found was that it can be accomplished, but it was nearly impossible to provide the correct environment in captivity. What the study found was that they needed huge cages for this to succeed, plenty of cover, and places to hide if things got hairy. Overall, it's difficult to provide in captivity, and just not recommended.
To summarize my thoughts and
opinions on this,
I don't believe hamsters should be kept together if you have the power. However, there is little evidence supporting either side of the argument. I think it's fair to make a claim either way as there are no conclusive studies (which is a real shame!). I would never ever hate or attack anyone for keeping pairs, and I don't think anybody should. It's their hamsters, and their choice. I simply advise against it. I think too many people claim "it's horrible and damaging, and you're torturing your hamsters" but I also think too many people claim "it's perfectly fine, they're social". I fall somewhere in the middle I suppose. I think that if something can be avoided, why wouldn't you avoid it? Just my thoughts on it