Ah! Lifelesstravelled! What a special and unique bond twins have. I have twin grandsons, age 6. It has been my priviledge to get to know them since infancy. I have observed them in the way they communicate, and seem to be protective of each other. The more assertive one of the two has said, "You leave my brother alone!" when he feels an injustice happening.
An elderly gentleman stopped my daughter one time while she was with the twins and said, "There is no closer bond!" And I believe this is true.
I had the fortune of knowing a fellow grad student at Marshall Univ. who was one of twins. He is confined to a wheelchair, the twin who suffered oxygen deprivation in the womb. He was adopted out to a family, away from his healthy brother. They were only reunited in young adulthood. And he told me that he and his brother, surprisingly, had many of the same interests and tastes in things.
I'm so glad that you posted here about the nature of twins!
Patty