Introduction and historical overview

Despite ubiquitous claims to scientific objectivity in the production of knowledge, few if any of our efforts at empirical or theoretical science are free of bias. All of our research efforts tend to be influenced by prior knowledge and beliefs concerning the phenomena that we study. Many of our efforts toward rigor in design are intended to control or compensate for sources of bias. Nevertheless, since it is impossible to eliminate human judgment and decision, biases continue to influence our work (see Gordon, Miller, & Rollock, 1990). Such is the case in the continuing pursuit of understanding relevant to issues concerning the relationships between intelligence, heredity, and environments. Our conceptions of each of these constructs are influenced by differential perspectives, which are often influenced by differences in the respective social position held by the investigator. One need only look at the long history of political contamination of this debate to see how much our efforts at explaining these relationships have been shaped by concern for differences in status attributable to class, race, and sex. In approaching this set of issues, we make no claims to objectivity. The authors of this chapter are conceptually biased in favor of epigenetic and interactionist conceptions of the origin and nature of human behavioral development. We are politically biased in favor of egalitarian and humanistic values as guides to inform social organization.