Many individual differences are interwoven in the negotiation process and impact the effectiveness of the outcomes. Personality traits will impact outcomes as extroverts tend to be weaker at negotiation because they will want people to like them. Intelligence is not an indicator of effective negotiation skills.
Mood and emotion can impact negotiations as anger is often an effective tool in distributive bargaining, whereas positive moods are helpful in integrative bargaining situations.
Gender can also impact negotiation effectiveness. Men and women tend to approach negotiations in the same way but may view the outcomes differently. Women may appear more tender in the process where men come across as tough. On the average, men are more likely to be negotiators than women.