Intellectual disability definition
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Understanding the Definition of Intellectual Disability
Introduction to Intellectual Disability
Intellectual disability (ID) is a term used to describe a condition characterized by significant limitations in both intellectual functioning and adaptive behavior, which covers many everyday social and practical skills. This condition originates before the age of 18 and affects an individual's ability to learn, reason, and adapt to new situations .
Core Features of Intellectual Disability
Impaired Intellectual Functioning
Intellectual disability is marked by impaired intelligence, typically defined as an IQ below 70. This impairment is more than two standard deviations below the population mean . Individuals with ID often have difficulty understanding new information and learning new skills, which significantly impacts their cognitive functioning .
Impaired Adaptive Behavior
Adaptive behavior refers to the collection of conceptual, social, and practical skills that people learn and perform in their everyday lives. Individuals with intellectual disability show significant limitations in adaptive behavior, which affects their ability to perform daily activities such as communication, self-care, and social participation .
Early Onset
The onset of intellectual disability occurs during childhood or adolescence, before the age of 18. This early onset is a critical factor in the diagnosis and classification of the condition .
Variability and Classification
Levels of Severity
Intellectual disability can vary in severity, ranging from mild to profound. The majority of individuals with ID have mild impairments, which means they can often function relatively independently with appropriate support. In contrast, those with severe intellectual disability require more intensive, lifelong support .
Sociocultural and Measurement Considerations
The definition and diagnosis of intellectual disability must consider sociocultural factors and potential measurement errors. Misunderstandings and misinterpretations of terms like "ability" and "cognitive" can lead to inaccuracies in diagnosis and classification. Additionally, the prevalence of intellectual disability can vary based on geographic and socioeconomic factors.
Historical and Evolving Definitions
Transition from Mental Retardation to Intellectual Disability
Historically, the term "mental retardation" was used to describe this condition. However, due to the derogatory connotations that developed over time, the term "intellectual disability" has become more widely accepted and used. This shift in terminology is reflected in the names of organizations and the language used in research and clinical practice .
Operational vs. Constitutive Definitions
The American Association on Intellectual and Developmental Disabilities (AAIDD) distinguishes between operational and constitutive definitions of intellectual disability. An operational definition provides the basis for diagnosis and classification, while a constitutive definition explains the underlying construct and supports theory and model development.
Conclusion
Intellectual disability is a complex condition characterized by significant limitations in intellectual functioning and adaptive behavior, with onset before the age of 18. Understanding the core features, variability, and historical context of intellectual disability is essential for accurate diagnosis, classification, and support. This comprehensive approach ensures that individuals with intellectual disability receive the appropriate resources and interventions to improve their quality of life and participation in society.
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