Language Delay and Disorders 3interaction (Wiig, 2004). These definitions of language address the multiple possibilities of expres-
sion and reception, symbolic encoding and decoding, and verbal symbolic thought. Each aspect is
discussed in this chapter, with case studies demonstrating clinical applications.
Etiology and Diagnosis of Language Delay and Disorders
Many disorders, diseases, defects, and deficiencies can cause language delay and disorders in
children. Some are organic and caused by physical irregularities in the child. Others are caused by
limited learning opportunities and environmental deprivation. The following are common causes
of language delay and disorders in children and considerations in their diagnosis.
Cognitive Prerequisites to Language Development
The role language plays in human thought has been debated for centuries. Some authorities
believe that language simply ref lects thought, whereas others are convinced that language and
thought are inseparable. Most authorities believe that language facilitates thought and thought
facilitates language. Language prob ably plays a greater role in adult cognition than it does in
children because adults engage in more abstract thought.
Certain cognitive prerequisites are necessary for a child to learn language. These include the
sequential development of ref lexive be hav iors, anticipation, causality, symbolism, categorization,
and so forth. A child must develop these abilities, and others, before he or she can acquire and use
increasingly higher levels of language. Several tests are available to assess cognitive prerequisites
for language acquisition in children, and parents can also be knowledgeable in for mants regarding
stage acquisition (Tanner, Lamb, & Secord, 1997; Tanner, Weems, Nye, & Lamb, 1988).
Intellectual Disability and Language Acquisition
Certainly not all children with language delay or disorders are intellectually disabled. As
will be discussed later, there are several language disorders in which children have normal or
above- average intelligence. However, intellectual disability is associated with delayed or dis-
ordered language acquisition. The effects of this condition on language development can be
marginal and result in mild language learning deficiencies. Severe intellectual disability can
profoundly impair or even prohibit functional language acquisition. The American Association
on Intellectual and Developmental Disabilities (2015) provides an up- to- date definition of
intellectual disability as a disorder originating before age 18 and characterized by significant
limitations both in intellectual functioning and in adaptive be hav ior as expressed in conceptual,
social, and practical adaptive skills.
Intelligence is a combination of mental abilities that allows the person to think logically, ratio-
nally, and effectively and to engage in adaptive prob lem solving. The operational definition of
intelligence is the intelligence quotient, a ratio of tested mental development to chronological age
( mental age divided by chronological age). Recently, some authorities have expanded the definition
of intelligence to include other categories in addition to verbal and per for mance abilities. Kagan
and Kagan (1998) propose eight intelligences, each with adaptive implications: verbal/linguistic
(word smart), logical/mathematical (logic/math smart), visual/spatial (art/space smart), musical/
rhythmic ( music smart), bodily/kinesthetic (body smart), naturalist (nature smart), interpersonal
( people smart), and intrapersonal (self smart). “The claim for all of these cognitive styles is that
across a wide range of types of information, a person approaches information with a consistent
style” (Kagan & Kagan, 1998, p. 3.5).