The Secret life of twins. Part one

Twins are an endless source of fascination as well as a prolific avenue for scientific research - this three part series attempts to unravel why. Program one looks at the inherent physical dangers of sharing a womb and how the timing of the split alters the type of identical twin you are. It follows two pregnant mothers carrying twins, one of whom has a natural birth, the other a caesarean section. Includes an interview with famous twins photographer David Tepplicher and the amazing physical co-incidences he has come across in his work. We follow Siamese twins in America joined at the head who not only shared a womb, but also part of their brain, which raises interesting questions about personality. Presented by Robert Winston.