Developmental language impairments with complex origins: learning from twins and multiple birth children

Various factors that make language development vulnerable in twins and multiple birth children are discussed. Researchers have investigated single explanations for language impairment in twins. However, this paper argues that in individual cases the language impairment is more often the outcome of a complex interaction of factors. Some factors play a greater part than others in some cases. It is suggested that clinicians can develop a dynamic model of language acquisition from understanding the effect of multiple birth and other exceptional circumstances on language acquisition. This model is needed to underpin investigations into individual cases of language impairment. An approach to assessment is described that identifies factors operating in individual cases of multiple birth, providing an essential precursor to implementing appropriate case-based intervention.