The social facilitation effect describes the change in the performance of the task under the influence of the presence of observers. The effect itself consists of two components: social facilitation in simple tasks and social inhibition in complex tasks. In the context of the dynamic development of new technologies, the question of the possible influence on human behavior by virtual characters gains importance. We attempted to critically describe and summarize current research on social facilitation in order to answer the question of whether it occurs in virtual environments. We found 13 relevant studies, 3 of which demonstrated social facilitation, 4 social inhibition and 1 demonstrated the whole effect. The conclusions drawn from the analysis are ambiguous. Firstly, we identified that 12 out of 13 analyzed studies failed to show the whole effect. Secondly, we encountered several shortcomings of the summarized research that further complicated its interpretation. The shortcomings: presence of the researcher, unclear usage of "agent" and "avatar", evaluation of activation, no pilot tests of observers and no description of how their characteristics are generated, among others, are discussed. Furthermore, we investigated the effect sizes and their variability. The average effect size for social facilitation was g = 0.18, CI [-0.28; 0.64] and for social inhibition g = -0.18, CI [-0.40; 0.04]. In social facilitation, a substantial level of heterogeneity was detected. Finally, we conclude that it is still too early to provide a definite answer to the question of whether social facilitation exists in Virtual Environments. We recommend limiting evaluation activation to the lowest possible level, conducting pilot tests prior to the experiment, avoiding the presence of the researcher in the experimental room and a clear distinction of "gent" and "avatar", as measures to achieve a better quality in future research.