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Manual of Diagnosis and Professional Practice in Mental Retardation: Preface

The field of mental retardation (MR) represents only one of a wide array of specialized areas in the clinical practice of psychology, nevertheless, it is especially distinctive. Nationally, a significant amount of society's resources in the realms of maternal and infant health, public health, and human services are dedicated to support and intervention for this population. Historically, Division 33 (Mental Retardation and Developmental Disabilities) of the American Psychological Association and the Psychology Division of the American Association on Mental Retardation have been important sources of research, practice, and advocacy, helping to expanding both the knowledge base of this specialty and to stimulate progressive public policy in service to people with MR.

Prior to the 20th century MR was generally defined in terms of the development of social and vocational competence. However, several factors led to a continuing evolution of the construct of MR, beginning at about 1900. At that time, most Western societies had transformed from agrarian or pastoral economies to primarily industrial and technical economies and the intelligence test was developed. The availability of these tests permitted prediction of childhood and adolescent success in education, because this was the criterion upon which they were founded. Because the economic viability of industrialized societies depends on the presence of an educated work force that can fulfill a wide range of productive functions, intelligence testing was widely and rapidly adopted as a social hygiene practice. Critically, testing represented an important turning point in the history of psychology; it was the first applied, or clinical, service that could be provided by psychologists, that was based on scientific methods, and that was in high demand. Testing brought psychologists out of their laboratories and into schools and adult service settings.

For the better part of this century the pragmatic criterion of MR was, thus, a tested I.Q. below a criterion level, assessed during childhood or early adolescence. For a period following the middle of this century, this criterion was set at -1 S.D. from the mean I.Q.; and many educational systems continue to use cutoff scores at or near this level as one criterion for participation in special education services. By the early 1970s there was recognition that although I.Q. scores in the range of -1 S.D. to -1.5 S.D. were more or les prognostic of general academic success, they were both (a) far less prognostic of adult vocational achievement and (b) classified too large a portion of students with MR. Consequently, since the 1970s, in classification protocols, the I.Q. criterion was shifted further to - 2 S.D. to avoid over-classification, resulting in a large reduction in the number of people classified with MR. However, it also became evident that although this shift resulted in improved prediction of academic attainment, adult outcomes for people scoring in the range of -2 S.D. to -3 S.D. remained highly idiosyncratic.

During the 1970s there was also growing appreciation of the importance of the development of social, pragmatic, and vocationally salient skills in rendering predictions of adult functioning among people scoring below I.Q. criterion ranges. Thus, "adaptive behavior" deficits or limitations associated with intellectual impairments were also introduced into the definition of MR in order to validate the impact of intellectual impairment on pragmatic and social functioning and to enhance prediction of adult functioning. Specification and use of the adaptive behavior construct has evolved through a series of successive nomenclatures. A third change in classification criteria has involved modest extension of the definition of the developmental period (the period during which MR is defined to first occur) from 16 to 18 years of age.

Changes in how MR is defined since the middle of this century have largely reflected changing conceptions of the threshold at which MR may be clinically determined to be present in the individual case. Sources of definitions of MR have included the American Association on Mental Deficiency (later the American Association on Mental Retardation) in successive editions of its classification manual, the American Psychiatric Association in successive editions of its diagnostic and statistical manual, and the World Health Association, in successive editions of the classification of diseases, and more recently, of handicaps and disabilities (Seltzer, 1983; Seltzer & Seltzer, 1991). The definition of MR used in this manual corresponds generally with the definition set forth by the American Association on Mental Deficiency in the early 1980s. It also corresponds generally with the definition set forth in the American Psychiatric Association's fourth edition of its diagnostic and statistical manual. The specifics and underpinnings of the definition are presented in the first chapter of this manual.

Mental retardation has been a rapidly evolving field of service and research during the second half of the 20th century. As a consequence of advances in psychological knowledge and changes in social policy, there have been consistent annual decreases in the extent to which people with MR, especially people with severe or profound MR, have been housed in institutions and steady increases in the extent to which supports and services involving community living are available in industrialized societies. These changes have occurred in the United States largely during the latter quarter of this century. They represent a return to a community orientation for people with severe disabilities, and a retreat from the institutional orientation, which had been established in the late 1800s as the primary element of benevolent public policy.

Psychological activities in the field of MR encompass assessment, treatment, advocacy, research, and evaluation. Psychologists have made consistent and significant contributions in each of these realms, as well as in the formulation and accomplishment of communitization of services. Nevertheless, one especially important legacy of institutional practices has been the development of specialized services for people with MR and resultant difficulty in accessing other service sectors such as mental health, social welfare, and vocational services. Although, as in the mental health sector, broad aspects of social policy in MR have been driven by the civil and individual rights movements since the 1960s, this field is also marked by a distinctive, and enduring philosophical orientation, termed normalization (Wolfensberger, 1972). Normalization involves provision of services and supports to people with disabilities in the ways that they are most normally provided in society for people without disabilities, and has provided a touchstone for the context and structure of service delivery and doctrines of least restrictiveness in treatment.

In the 1980s the perspective of normalization has been recast as social role valorization, which places greater emphasis on social psychological dimensions, such as social acceptance and personal integration and productivity, of roles of people with MR in society (Wolfensberger, 1983). This shift toward a more social orientation in philosophy has been reflected in aspirations to increase the individualization of services and supports and, for example, to replace group homes with individual living situations or, at least, provide living situations that are more like families in size and vocational situations in which people with disabilities are integrated with other workers. This shift has also fueled deprofessionalization in the field, which increases the difficulty of implementing prescriptive clinical treatments when they are needed on an individual basis, as well as resistance to use of treatment protocols that conflict with philosophical strictures. Although these difficulties preexisted contemporary interpretations of philosophic goals in the field of MR, they have heightened during the past decade and present an immense challenge to the scientist-practitioner.

At the same time that these side effects of otherwise benign changes in MR policy have occurred, there has been a growth of anti-scientific sentiment in society and within elements of academia that presents a severe challenge to behavioral science and the development of effective social technologies. The validity of the methods and findings of behavioral science from the standpoint of an intellectual movement known as post-modernism or constructionism, in which knowledge is specified to be socially constructed or socially derived (Gergen, 1994; Guerin, 1992; Sampson, 1993). In the field of MR postmodern perspectives have become embodied in social role constructions of MR (Biklen & Duchan, 1994; Luckasson, et al., 1992) in which the environmental component of person x environment interactions is the core construct and elucidation of cognitive, affective, and behavioral functioning of people with MR, as well as other findings of behavioral science, are largely discarded.

Social role formulations of MR are not novel, and have their origins in the social science literature of the 1960s and 1970s (Braginsky & Braginsky, 1971; Goffman, 1961; Gold, 1980; Szasz, 1961; Ullman & Krasner, 1975). Ironically, one of the earliest and specific explications of social role development in mild MR was set forth by a behavioral scientist (Bijou, 1963). Moreover, respondents to postmodern criticism have noted that behavioral science may serve a purpose in identifying the utility of social policies (Kendler, 1993) and ascertaining matters of fact or pragmatic import that transcend construction (Gergen, 1994; Guerin, 1992; Whitehurst & Crone, 1994).

The organization and content of this manual reasserts the validity of the scientist-practitioner, behavioral science perspective in the practice of psychology in MR. Although it has not been possible to address all subspecialization, contextual, and theoretical concerns in this volume, the principal areas of individual functioning and development, and the major areas of clinical service by psychologists are encompassed here. As a professional manual, this volume serves as a consolidated source of findings from psychological science and practice for psychologists practicing in the field of MR. For psychologists in general community practice, or in specializations such as rehabilitation, pediatric, or child and family services interested in serving people with MR, this volume may usefully introduce practitioners to the broad literature indicating proven clinical practices. Finally, use of this manual as a resource to communicate the findings and practice implications from psychological science to practitioners in other professional and health disciplines is strongly encouraged.

John W. Jacobson, Albany, NY
James A. Mulick, Columbus, OH
November, 1994

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