Dwarves will sometimes make friends, and this gives them a happy thought. The likelihood of two dwarves becoming friends increases, as both spend time socializing instead of working. But be warned, although dwarves get happy thoughts from making friends and talking with them, they will become quite sad if a friend dies. This is a common source of fun.
Note that friendship is not reciprocal: A dwarf may be friends with another dwarf who isn't even a passing acquaintance.
There are several ways of avoiding the dangers of friendship. The first and hardest option is to ensure that no one ever idles. The second is to designate a HUGE meeting area, so that idlers won't be anywhere near each other. The best way, however, is to provide everyone with a personal bedroom. When this is combined with the absence of a designated meeting area, idle dwarves will spend their time in their bedrooms, alone. Extra care must be taken with soldiers in the same squad, for not only do they spend a lot of time together, and thus can easily socialize when they're off-duty, but they also are the most likely to die (especially if they're inexperienced recruits). This often leads to the entire squad becoming depressed over the death of a single soldier; combined with the fact that the soldiers are most likely equipped with armor and weapons, this means that tantrums resulting from a soldier's death can be