Abstract: Behavioral genetics is an interdiscipline based on the development of several branches of science. Dating from the end of 19th century, behavioral genetics has placed us in the third century. Whether from Mendel’s single-gene law to interplay between multiple genes and environmental factors explaining complex human behaviors, or from traditional quantitative genetics to linkage and association studies and then to applying tools of functional genomics, there have been revolutionary breakthroughs in behavioral genetics. Although a clear elucidation of how genes affect behaviors is still in the fetal stage, there is little doubt that the development of behavioral genetics will provide a better understanding of behaviors of human beings, relieve the suffering from some complex disorders and ultimately lead to improvement of the whole society.

Key words: behavioral genetics, multiple-gene system, quantitative genetics, linkage and association studies, functional genomics