Abstract: Jackson had compared executive function (EF) of deaf children and that of normal children, and found that there was no difference between the two groups. However, it is known that language relates to the development of theory of mind and executive function. In the present study, we argued that Jackson’s study had three problems: 1) there were 4 kinds of deaf children in that study, that is, these samples had no homogeneity; 2) compared to the 4~7-year-old normal children, the age distance (4 years 10 months to 12 years 11 months) of the deaf children was so large that his study could not reveal the developmental feature of the executive function of deaf children; 3) Jackson used the A-not-B task and its 3 modifications. The tasks were too simple to measure the development of executive function accurately.
Our study improved on Jackson’s by employing the standard Dimensional Change Cards Sorting (DCCS) task to test 76 3~8 year-old deaf children (whose intelligence was normal) of hearing parents and 78 3~5.5 year-old normal children to compare the development of executive function between these two groups. Thus, we were able to explore the characteristics of development of the executive function and the level of development of the deaf children.
The results indicated that there was no significant difference between 3-year-old deaf children and 3-year-old normal children. Normal children developed rapidly during 4~4.5 years, whereas development accelerated after 6 years for the deaf children; the performance of 7-year-old deaf children was equivalent to that of 5-year-old hearing children. That is, deaf children were late by about 2 years in EF development in comparison to normal children. The developmental delay could be explained by three aspects: 1) there is a difference between the language symbol system and the special symbol system of the deaf; 2) deaf children could have a deficit in planning and flexibility; 3) deaf children could have difficulty in naming and labeling strategies, and have a deficit in the attention mechanism. Compared with previous research reports that found that the theory of mind in deaf children tended to develop 7 years later than normal children, the development of executive functioning is not consistent with development of theory of mind

Key words: deaf children, executive function, theory of mind, cognitive complexity and control, selective attention