Benjamin Radford via LiveScience
Many identical twins — perhaps as many as one in five — claim to share a special psychic connection. About one out of every 30 babies born in the United States is a twin, and identical twins are especially interesting because they have the same genes and are alike in many ways. Brothers and sisters can be close, but some twins claim to know what the other is thinking or feeling. It’s an intriguing idea, but what’s the truth behind it? Coincidence, psychic powers or something else?
This sort of psychological connection isn’t necessarily mysterious, of course: any two people who know each other very well and who have shared many common experiences — including non-twin siblings, old married couples, and even best friends — may complete each other’s sentences and have a pretty good idea about what the other person is thinking.
The idea of twin telepathy has been around for well over a century. It appears, for example, in the 1844 Alexandre Dumas novella “The Corsican Brothers.” It tells the story of two once-conjoined brothers who were separated at birth yet even as adults continue to share not only thoughts but also physical sensations. As one twin describes, “However far apart we are now we still have one and the same body, so that whatever impression, physical or mental, one of us perceives has its after-effects on the other.” The 2013 best-selling novel “Sisterland” by Curtis Sittenfeld also tells the story of twin girls who share a psychic connection.
Most of the evidence for twin telepathy is not scientific but instead anecdotal.