Social skills are used mainly by the Expedition leader, Manager and Broker. They are used in interactions between the dwarves in your fortress as well as when talking with liaisons and merchants. Social skills are acquired at embarking, while performing the above administrative tasks or while attending parties. The starting dwarf with the most social skills will almost always become the Expedition leader, who will automatically become your first mayor, so when giving social skills to your starting dwarves don't give them to one whose preferences will lead to obnoxious mandates when s/he becomes mayor.
The following list is based on the skills listed in the nobles screen when replacing a noble.
 List of Social Skills
 Miscellaneous conversational skills
It is unknown what specific circumstances make one or another of these useful; most of them are trained by parties, conversation between two or more idle dwarves, and trading. The latter fact implies that they are useful in trading, perhaps to get a better deal. They are also listed as mayor skills.
- Judge of intent
 Broker skills
All of the conversational skills listed above are trained by (and thus, presumably, used in) trading, presumably to increase the chances of a deal being successful. Judge of intent skill is particularly important as it allows a broker to see how a trader feels about a particular deal. Note that the Appraiser skill, which is not a social skill, is also very important during the trading process.
 Mayor Skills
While all the conversational skills are important for a mayoral dwarf seeking reelection by making friends, dwarves with these two skills can reduce the likelihood of tantrums by being complained at or cried on (which creates a happy thought for the other dwarf). These skills are also all listed as relevant for the manager.
 Gaining Social Skills
Dwarves train their social skills when idling in meeting areas or attending parties and they are standing near another dwarf. All social skills seem to train at roughly the same rate, though their personality traits will determine which skills they train - for example, a very self-conscious dwarf will not gain Comedian skill. See personality trait for more information.