Someone Else's Twin: the story of an identical twin mistakenly switched at birth

Certain identical twin behaviors are unmistakably genetic.
For instance, just as soon as Matthew and Jonathan learned to walk, we noticed a funky run they do when they are between activities, trying to decide what to tackle next. They put their heads down and their arms to their sides with their hands slightly behind them.
Then they run from one side of the room to the other and back again along the same paths, continuing until they have decided on their next moves. They always criss-cross if they happen to run at the same time.
They never run together.
It's clearly a subconscious thing. Their minds are elsewhere while they run and they seem unaware that they are doing anything at all. Just for fun, we'll join them once in a while. They'll stop, give us puzzled looks and then put their heads down and go at it again.
With their identical DNA, monozygotic twins have long been subjects of study in the debate of nature verses nurture. It's hard not to wonder about nature's influence when, as parents, we see our twins cock their heads the same way or sleep in the same positions or present the same expressions when they taste food they don't like.
That's why I find the subject of Nancy Segal's latest book so intriguing.
I ordered her book, Someone Else's Twin, moments ago after reading this review from The Wall Street Journal.
Segal is a twin herself and an academic psychologist who specializes in twins. In Someone Else's Twin, she relates the story of  identical twins from the Canary Islands who found each other at 28 years old after one was mistakenly switched with another in the hospital at birth.
Like Matthew and Jonathan, the girls each had her own sac and placenta. The mother never suspected the girls had been switched because she assumed her babies were fraternal. They united only because a clerk at store they both frequented insisted they looked exactly alike and that the should meet.
According to the review, Segal manages an engaging narrative while also drawing sound conclusions about the women and commonalities between them that extend beyond the physical. ("The two of them realized that they push their food away when eating with a fork or spoon and fold their lips over their teeth when they get anxious.")
Other books have been written about twins separated at birth, but with Segal's expertise, Someone Else's Twin is likely to be the best among them.
It should arrive in a few days.
I should be immersed in it soon after.
I'll let you know.

First day of pre-kindergarten

Matthew (in yellow) and Jonathan couldn't wait to get inside their new classroom on Thursday.
It's hard to believe that next year they'll be heading into kindergarten.
And, no, Matthew is not taller than Jonathan.
Matthew is slightly elevated, though I'm sure he'll try to use these photos as proof during one of their "I'm taller than you are" arguments.