Abstract: Since Wright presented the three-component psychological system in the field of transitivity inference, the model has come to be one of the focuses in the transitivity inference researches. This article chiefly introduces its theoretical background, basic hypotheses and structure. The three-component psychological system is based on the classic Piagetian theory and information processing theory. This represents three main processing mechanism (the transitive-switch mechanism, the order-extraction mechanism and the coordinative response mechanism ) in the transitive inference, and each processing mechanism has different strategy. Furthermore, future research orientation is probed in the article.

Key words: transitivity inference, three-component psychological system, the transitive-switch mechanism, the order-extraction mechanism, the coordinative response mechanism.