Developmental influences in teaching language forms to individuals with developmental disabilities.

Area of Science:

• Developmental Psychology
• Linguistics
• Special Education

Background:

• The typical sequence of language acquisition in children is well-documented.
• Current language curricula for individuals with developmental disabilities often assume this normal developmental sequence is optimal for intervention.

Purpose of the Study:

• To empirically test the assumption that language intervention for individuals with developmental disabilities should mirror the normal developmental sequence.
• To investigate the efficacy of teaching early versus later emerging phonetic sounds and syntactic structures.

Main Methods:

• Two studies were conducted involving individuals with developmental disabilities.
• Participants were taught phonetic sounds and syntactic structures representing varying stages of normal language development.
• Acquisition rates, order of acquisition, and long-term retention were assessed.

Main Results:

• Earlier emerging language forms were acquired significantly faster (fewer trials) than later emerging forms.
• Acquisition of later emerging forms never occurred without prior acquisition of earlier forms.
• Earlier forms demonstrated superior production accuracy 6 months post-intervention compared to later forms.

Conclusions:

• The findings support the use of the normal developmental sequence as a basis for language curricula for individuals with developmental disabilities.
• Intervention strategies should prioritize earlier developing language skills, as they appear foundational for subsequent learning and long-term retention.