Abstract
Theory of mind (ToM) is the ability to understand other people’s mental states. No clear findings have been found in animal studies. This suggests that the difference between great apes and humans, who have similar social-cognitive structures, may be due to theory of mind. This study investigates the difference that may cause ToM by compiling the findings and ideas about how Tom is developed. Studies show that language skill, which is another crucial difference, predicts ToM. Language helps to ensure participation in society and the interaction of human with the environment may have paved the way for predicting others’ mental states. Communication with the social environment also includes knowledge transfer and learning. This review is aimed to contribute to the literature with the idea that learning type can evolve into a complex cognitive and social structure together with the social environment and language, making modern humans different from animals.