Reply to Commentators.

Abstract

We thank Professors Brody (2007, this issue), Gottfredson (2007, this issue), and Steinberg and Grigorenko (2007, this issue) for their thoughtful comments. Hopefully our reply will further debate on this important topic. We said that so many definitions have been given that intelligence itself is a fuzzy (i.e., ill-defined) concept. Gottfredson claims this is not so, and offers what she presents as an agreedupon definition, based on statistical analyses of intelligence test scores. Sternberg and Grigorenko take us to task for not including emotionality and personal goals, which are part of Steinberg's notion of successful intelligence. Considering that these opposing criticisms come from well-established, knowledgeable investigators, we maintain our point. The definition of intelligence is fuzzy. One of the important steps in science is the creation of definitions that, in Plato's terms, carve nature at the joints. The distinction between acceleration and velocity was crucial to the advancement of physics. The study of intelligence would benefit by an analysis of clear definitions rather than claims that one or another group of investigators has discovered the right one. We believe that Gottfredson's emphasis on extant tests is too narrow, but that Steinberg and Grigorenko would cast such a broad net that it would make the study of intelligence unmanageable. We offered an intermediate position. We hope this matter will receive discussion in future papers. Brody is concerned that advances in understanding intelligence will depend upon the identification of new sources of evidence. We agree, but add that our concerns about design and interpretation will apply to studies using these new sources. The remaining criticisms by Gottfredson and Sternberg and Grigorenko can be divided into major issues and specific comments. We deal with the major issues first, beginning with Sternberg and Grigorenko, and then move to the specific points. Sternberg and Grigorenko argue that race is an invalid concept because (a) there are no infallible genetic, physical, or, for that matter, social indicators of race; (b) different societies vary in their categorization of racial groups; and (c) there is greater intraracial genetic variation than there is interracial variation.