Why does unethical behavior plague legal negotiation? Traditionally, scholars have assumed that “good” people behave ethically and “bad” people do not. But an emerging body of social science research finds that cognitive and motivational biases often enable and even encourage otherwise good people to unwittingly act badly. This lecture will explore how this research in the field of “behavioral ethics” should change how we think about the way lawyers negotiate, and how lawyers themselves or the legal system can respond.