Behavioral Economics extends standard neoclassical economics models to incorporate features that are consistent with observed human behavior. The text explores (i) pro-social behavior such as cooperation, trust, reciprocity, and voluntary contributions to public goods, (ii) intertemporal choice that may be distorted by present bias, and (iii) choice in uncertain environments that are influenced by decreasing sensitivity and relatively painful loss. It also explores the role of natural selection in shaping human behavior, highlighting the co-evolution of genes and culture.