The ability to form long-term social memories is essential for remembering faces and developing social bonds. Scientists have now discovered that the tiny CA2 region in the hippocampus is involved in the linking up of memory fragments (consolidation) to form long-term memories, and that a neuropeptide, substance P, is involved in this process. Since CA2 is responsible for social memory, this finding has significant implications for how long-term social memories are formed. – Source