For at least two centuries, there has been speculation that there is something “special” about how twins communicate, notably monozygotic (MZ) or “identical” ones, but also though less frequently if they are dizygotic (DZ) – fraternal or non-identical. (All twins mentioned here are either MZ or assumed to be, except where otherwise stated). “Are twins telepathic?” is a regularly asked question to which attempts to give a convincing answer have only recently begun to be made. One may also formulate this question in other ways, using the language of 21st century science, e.g. “Do twins demonstrate what we might call, if only by way of an analogy, macro-entanglement?” There is now instrumentally recorded evidence suggesting that some do, but not all of them, and only under certain very specific conditions. Theoretical physicist Sir Roger Penrose has even suggested that consciousness is an effect of quantum entanglement, “which might have implications for the twin bond and the nature of shared consciousness between twins”. The possibility of such implications needs further study
