One
INTRODUCTION AND OVERVIEW

During the writing of this text, the California State Department of Education (CDE) issued a memorandum, dated September 14, 2022, for all Special Education Local Plan Area Directors in the state (California Department of Education, 2022). The memorandum effectively reversed (in part) the prohibition against administering IQ tests to African-American students for any special education purpose in California schools. The memorandum was issued in response to an earlier 1986 CDE memorandum which expanded Judge Peckham's original 1979 decision in the Larry P. v. Wilson Riles trial. Peckham's decision prohibited the use of IQ tests for placing Black students in programs for (what was then called at the time) the Educable Mentally Retarded-on the grounds that (in his determination) IQ tests were culturally biased against African-American pupils. The CDE's 1986 memorandum expanded Judge Peckham's decision to prohibit the use of IQ tests for Black students in California for any special education purpose (including gifted identification; see California Association of School Psychologists, 1987; Frisby & Henry, 2015).

The prohibition had been in effect in California for over three decades, engendering much confusion and misinformation across school districts and among school psychologists as to what tests were or were not allowed to be used-as well as what procedures were needed to properly evaluate Black students for special education. Whatever procedures were used, there was uniform agreement that the quality of assessment services for Black pupils had taken a severe hit.

The most recent 2022 memorandum allows IQ tests to be used with Black students for any special education category except intellectual disabilities (IDs)-which essentially retained Judge Peckham's original 1979 decision. Undoubtedly, this recent memorandum was greeted with a palpable sense of relief among most clinicians in the state; however, this did not address what was fundamentally problematic with California politics as it relates to the use of IQ tests (e.g., see Thomas, 2019). This fundamental problem relates to widespread confusion and the general lack of consensus among professionals as to what intelligence test bias is, how it is investigated in the science of psychometrics, and the extent to which it may (or may not) exist in commonly used intelligence tests.

The effects of the Larry P. trial on school psychology in California were witnessed up close by this author, as I was a school psychology graduate student attending a California university in the early 1980s. At that time, all school psychology students were required (as they are now) to take classes on administering and interpreting intelligence tests, and training programs were required to provide school districts with competent graduates in this regard. Unfortunately, instead of there being a widespread consensus about the relationship between intelligence testing and cultural bias in school psychology training, training programs instead resembled autonomous fiefdoms whose reactions to the Larry P. decision reflected each program's idiosyncratic attitudes. Some California programs reacted to the Larry P. decision as one of the worst things that could have ever happened to school psychology in the state, while other programs celebrated the decision as a welcome advance for equity and social justice.

At about the same time, world-class educational psychologist Arthur Jensen published Bias in Mental Testing (abbreviated hereafter as BIMT) in 1980. BIMT is a 780+ page text that, to this day close to half a century later, remains unmatched in its impact on the scientific understanding of bias in mental testing, generally, and intelligence testing, specifically. While test bias studies were being conducted pre-1980, there was little effort to comprehensively and exhaustively consolidate, organize, summarize, and evaluate such studies under a coherent picture of what was being learned about mental test bias. No other text up until 1980 had made such a concerted effort to provide clear analyses as to popular misconceptions about test bias that were widespread among professional organizations, the general public, and the popular media (which unfortunately, persists up to the present day). No other text before 1980 had provided clear and precise scientific definitions for the many different forms of bias that could potentially affect mental tests. Studies of test bias after 1980 owe a huge debt to the concepts provided in BIMT. This explains why so many references to this important book appear in the present text.

Despite BIMT's seismic impact on the world of psychometrics, its influence has barely registered on graduate students taking clinical training courses in intelligence testing. Such courses are under tremendous pressure to expose students to so much information in so little time. To illustrate, intelligence testing courses are required to teach students: (a) the history of intelligence testing; (b) how to use and score a wide variety of different intelligence tests; (c) the clinical skills necessary for administering, scoring, and interpreting tests with actual subjects; (d) how to write clinically useful reports that detail the results of testing; and (e) how to master the basic measurement concepts of reliability, validity, measures of central tendency, measures of variability, correlation, calculating standard scores, computing confidence intervals, interpreting information from the normal curve, and interpreting factor loading tables. With ongoing advances in computer technology, many students also must learn how to administer Q-global assessments on laptop computers as well as how to interpret printouts generated from computer scoring programs. It comes as little surprise, then, that students in assessment courses have so little sustained exposure to concepts of test bias (which require familiarity with all of these other topics as pre-requisite knowledge). For many training programs, didactic instruction on test bias is, at best, an afterthought.

Compounding this problem is the inevitable confusion that occurs when students experience virulent anti-IQ test hostility from journal articles, newspaper stories, television news programs, or activist peers and/or professors, which they may encounter in their training programs or at professional conventions. They will no doubt hear endless accusations that "intelligence testing is culturally biased"-based on little more than a vague awareness of significant differences in mean intelligence test scores achieved by population subgroups. If students are not grounded in sustained instruction on the topic of test bias, then many may begin to wonder if they are "doing something wrong" by administering IQ tests as a basic requirement of their professional service in applied settings.

There are so many excellent and important books, book chapters, and journal articles that have been written on the topic of intelligence test bias since 1980 (many of which are cited in this text). Why, then, is another text on the topic needed? Many publications on test bias are written with measurement specialists, psychometricians, and researchers in mind. In contrast, this text was purposely designed to be most useful instead to applied clinicians who may not have the time, resources, or inclination to familiarize themselves with the massive literature on IQ test bias-much less conduct original research on the topic. The applied clinician is most likely to be more interested in how the use of IQ tests-from test selection to test scoring-may be impacted by test bias. As such, this book includes 10 chapters, the content of which is summarized below.

Chapter 2: Sources of Bias Claims in Intelligence Testing: A Brief Overview. Criticisms of IQ testing have been around as long as IQ testing has been around. In addition, accusations of cultural bias against IQ tests will exist as long as they are used in diverse societies. Some criticisms stem from a basic discomfort that many feel from the notion that a quantitative score can be derived from the evaluation of a trait that is viewed by many as intensely personal and unmeasurable. More frequently, critics align with deeply felt sociopolitical ideologies that often collide with the results of mental testing. This chapter provides readers with a sampling of what critics have said about IQ testing over seven decades. In addition, numerous sources of IQ test criticisms that originate from academia, organized advocacy groups, the courts, and the popular/print media are discussed. The chapter closes with a brief overview of counter-narratives that have defended IQ testing.

Chapter 3: Bias and IQ Test Selection. This chapter begins with a basic discussion of why intelligence tests are needed in applied human services, and the criteria that enter into the selection of good IQ tests from the perspective of the applied clinician, the measurement specialist/psychometrician, and test publishing companies. This material includes an in-depth discussion of the popular concept of "test fairness"-used by test companies to market their products. The chapter concludes with a brief discussion of the specific assessment features and strengths of popular individually administered IQ test batteries currently available at the time of this writing.

Chapter 4: Bias and IQ Test Standardization. One of the earliest and...