This sort of correlates with the theory that poor countries are happier because of their "less developed" lifestyle that encourages friendship and camaraderie over accomplishment and material gains.
Not sure if it's the "less developed lifestyle" or the adversity. When you have to fight corruption at each step, when there are problems with basic amenities like water, electricity, land shortage, class divides, language divides, then you do find a lot of friends who have the same issues as you.
The above sounds a bit silly or ironic, but one hears of the miners who were trapped for months who built great friendships during those hard times. I am also reminded of that movie "Plenty".