24. Identical Twins
While fiction has a lot to do with the myth behind shared pain and stimuli in identical twins, several studies have proved that identical twins do have similar responses to stimuli. This was famously demonstrated by TV person Derren Brown.
The reason for this phenomenon could be shared genes, similar upbringings, and life experiences that identical twins go through.
The controversial case of twin studies by Peter Neubauer and Violet Bernard has been involved with studying the lives of separated identical twins as well.