Shared pain or empathy?

I met a elderly man in the mall a few months back who stopped to admire the twins. He is an identical twin, he told me. He said that one day a few decades ago, when he was home in Cincinnati, his arm began to ache terribly. He sensed that something was wrong with his twin, who lived five hours away in Cleveland.
He called several times.
No answer.
Then his twin called him.
His twin had broken his arm.
"You just wait," the man said with a grin.
I have heard and read many similar stories since the twins were born, but I was a skeptic. There is no scientific evidence that identical twins feel each other's pain. It is all anecdotal and, probably, highly exaggerated, I figured.
But an incident today made me think again.
I had taken the boys to a Mom's Day Out program that I was considering for the fall. I immediately disliked the place. Several kids played aimlessly in a cramped room while the caretaker sat there like a bump on a log. The director had explained to me that this particular program was simply a babysitting service. But, come on. I would fire any sitter who didn't interact with my kids.
Still, I decided to give it a chance and let my boys play a while.
As I was trying to persuade a 2-year-old boy that Jonathan's head was not a highway for his dump truck, I heard an ear-piecing scream from Matthew. He was sitting under a table and another boy was crouched behind him.
I figured Matthew had tried to stand and had bumped his head.
But his reaction was far too strong for that.
Before I could even move, Jonathan looked at Matthew and released an identical scream. And there I stood, between the boys who were crying and screaming so hard that their faces were turning blue (The caretaker, of course, just sat there and did nothing).
Neither boy stopped crying until we left that place.
Later, as I lifted Matthew's shirt to put on his PJs, I found the source of his pain: a perfectly round bite mark from a child who clearly had all of his teeth and knew how to chomp hard enough to break the skin.
Now, mostly likely, Jonathan saw the look on his brother's face and, because they have been together every day since the moment they were conceived, he sensed what Matthew was feeling.
Maybe, even at only 15 months old, Jonathan has already developed empathy.
But maybe not.
I am still a skeptic, but I am a skeptic with an open mind. That is, toward the concept of the twins feeling each other's pain. My mind is closed to the Mom's Day Out program.
When this mom goes out, she'll be bringing her twins.