Psychological researchers typically distinguish five major domains
of individual differences in human behavior: cognitive abilities,
personality, social attitudes, psychological interests, and
psychopathology (Lubinski, 2000). In this article we: discuss a
number of methodological errors commonly found in research on human
individual differences; introduce a broad framework for
interpreting findings from contemporary behavioral genetic studies;
briefly outline the basic quantitative methods used in human
behavioral genetic research; review the major criticisms of
behavior genetic designs, with particular emphasis on the twin and
adoption methods; describe the major or dominant theoretical scheme
in each domain; and review behavioral genetic findings in all five
domains. We conclude that there is now strong evidence that
virtually all individual psychological differences, when reliably
measured, are moderately to substantially heritable
