ERIC Number: ED313837
Record Type: RIE
Publication Date: 1989-Jul
Deafness as a Natural Experiment: A Meta-Analytic Review of IQ Research.
Braden, Jeffery P.
The literature describing deaf persons' intelligence was subjected to a quantitative and qualitative review in this analysis of 85 studies containing independent samples of 43,177 deaf subjects. First, bibliometric analyses were conducted to define the scope, dissemination, and trajectory of the research investigating deafness and Intelligence Quotient (IQ). Second, meta-analytic techniques were applied to the results of studies captured in the review. Bibliometric results showed that the field experienced steady but slow growth over time, yet the field remains isolated, disconnected, and nonexperimental in nature. Meta-analytic results showed deaf persons' nonverbal abilities were in the average range, but the type of tests affected IQs. Performance tests yielded slightly higher IQs than other nonverbal tests, and both yielded higher IQs than verbal tests. Genetically deaf persons had above-average IQs in contrast to the average IQs of nongenetically deaf persons or normal-hearing peers. It is concluded that environmental disadvantage clearly inhibits development of verbal intelligence and that nonverbal abilities are not affected by the environmental disadvantages experienced by deaf persons. It is proposed that deafness as a natural experiment might be better understood as a "disadvantaged minority" experiment, rather than a "language deprivation" experiment. (Author/JDD)
Publication Type: Speeches/Meeting Papers; Reports - Evaluative
Education Level: N/A
Authoring Institution: N/A
Note: In: Martin, David S., Ed. International Symposium on Cognition, Education, and Deafness (2nd, Washington, DC, July 5-8, 1989). Working Papers: Volume I.