Social science and neuroscience perspectives represent two ends of a continuum of levels of organization studied in psychology. Human behavior as a whole unfolds at social levels of organization, whereas much of the research in psychology has focused on cognitive and biological pieces of this whole. Recent evidence underscores the complementary nature of social, cognitive, and biological levels of analysis and how research integrating these levels can foster more comprehensive theories of the mechanisms underlying complex behavior and the mind. This research underscores the unity of psychology and the importance of retaining multilevel integrative research that spans molar and molecular levels of analysis.