Abstract: ［Purpose/Significance］Information cocoons and echo chambers are both connected with humans’inherent tendency to approach what they like and/or avoid what they dislike. For lack of exposure to the heterogeneous information from the outside, one’s information horizon becomes more and more limited, which in turn reinforces his or her selective information behavior. This study aims to reveal the status quo of existing related research and identify future research trends.［Design/Methodology］This study originally attempted to conduct a systematic review on the existing studies of information cocoons and echo chambers, respectively. However, there existed no empirical research on the former. Hence, this study instead surveyed the literature on selective exposure for its high relevance to information cocoons.［Findings/Conclusion］Selective exposure studies, basically driven by the social issues pertinent to the two dominating topics,i.e., politics and health; echo chambers studies identified various echo chambers, such as political, science/conspiracy, health, policy, scholarly echo chambers, while a minority of the studies doubted the existence of echo chambers. Information cocoons, selective exposure, and echo chambers all refer to the overall behavior patterns of dispositional selection. The existing related studies were limited to the cognition dimension of human attitudes when examining the influence of attitudes on information selection while neglecting the affect and conation dimensions; and they failed to distinguish between single behavior occurrences and overall behavior patterns which is not helpful to the change of overall behavior patterns.［Originality/Value］This study contributes a compressive overview of the literature on information cocoons, selective exposure, and echo chambers. The meaning and relationships among the three concepts were clarified, which led to the new concept of "narrowed information universe" that emphasizes the behavioral patterns of selective approach/avoidance in information acquisition. Useful implications were engendered for the future research on the narrowed information universe.

Key words: Information cocoons, Echo chambers, Selective exposure, Narrowed information universe, Systematic review