The twins thing is easily explainable by a programming reference. Seed 2 instances of the same random generator class with the same seed and have them run a million numbers on different computers... the millionth number will always be the same. Humans are just big wet sloppy computers with a little more noise than our PCs (environment is different for everyone, even identical twins are not in the exact same space) so it's likely that twins will more often than anyone else be thinking in parallel with each other from time to time.