Question: is there any subtle differece between social cognition and theory of mind?or they are exactly the same?

Answer1:it's not same.social cognition and theory of mind is quite different.

Answer2:There is a huge difference. Social cognition is a very broad general term used in developmental and social psychology [usually] to refer to cognition of social entities [persons, groups, etc.] and sometimes to the effect of social interaction on cognition in general [as in the research of Doise]. In contrast, theory of mind refers to a large but narrower set of phenomena in developmental psychology, refering to the hypothesized developing idea that other people have cognitions differing from one's own and from each other, in short that the world is represented in people's minds and that this representation is not equivalent to reality.

Answer3:¡¡I just wrote a thesis on that subject.¡¡Even within the research of Theory of Mind (ToM), little consensus exists amongst theorists about what is and is not within its sphere of influence.¡¡The best I'Ve seen yet is Damasio et al, Bechara et al 2000-4 articles with those terms in the titles.¡¡Go to Pubmed and type in the terms to find the abstracts for the articles. In a nut shell, the simple difference between social cognition and ToM is the degree of cognitive and emotional processing and the mechanisms behind the representational content of them.¡¡ToM requires a knowledge that others have sets of different emotions, beliefs, desires, intentions, goals, decpetive tendencies, and senses of Humor; a complicated feat that does not come on-line until appropraiate linguistic and abstract representational capacities develop--roughly by around age 3-4.¡¡On the other hand, Social cognition simply refers to any thought content that is derived from an interpersonal exchange and occurs early such as 10-12 months (Lewis, 2000) as in "social referencing" when a baby judges to approach or withdraw from specific stimuli based on the eye gaze and facial expressions from a caregiver.¡¡It is a fascinatining area of research with mega implications toward future research--I'm glad to see people inquire about the subject.