Abstract: The question of whether there is greater intra-lingual Stroop interference in Chinese than in English was examined in a meta-analysis, which integrated research findings from 14 published and unpublished studies. A total of 15 Chinese samples and 19 English samples were analyzed. Stroop interference was expressed both in terms of reaction time (RT difference as well as RT ratio) and in terms of an effect size index (Hedge's g). No difference was observed between Chinese and English, either in RT difference, RT ratio, or in Hedge's g. This was the case regardless of the type of Stroop task (color-word or picture-word) and the type of neutral stimuli (homogeneous form or heterogeneous form) employed. The results also held when additional English samples were added into the analyses. The findings contradict the orthographic variation hypothesis, which predicts different intra-lingual Stroop interference between different writing systems. After reviewing and evaluating other kinds of evidence which were cited previously as supporting the hypothesis, it is concluded that the orthographic variation hypothesis bears no empirical ground and is best rejected.

Key words: Orthographic Variation Hypothesis, Stroop Interference, Chinese, English