Quote from : The Future of the Mind: The Scientific Quest to Understand, Enhance, and Empower the Mind Book

In science fiction, telepaths often communicate across language barriers, since thoughts are considered to be universal. However, this might not be true. Emotions and feelings may well be nonverbal and universal, so that one could telepathically send them to anyone, but rational thinking is so closely tied to language that it is very unlikely that complex thoughts could be sent across language barriers. Words will still be sent telepathically in their original language.