Left-Handed People Killed Their Twins!
For a while scientists had a theory that left-handed people started out as twins while in utero. Their belief was that in a set of twins one is usually right-handed and the other left-handed. Genetic and nurturing factors can also affect handedness, but they can’t explain it completely in many cases. Maybe all lefties were the result of only one twin surviving the cage fight that is fetal development.
It wasn’t until ultrasounds, and fearless cameras capable of surviving the uterus, that scientists discovered their hunch was right. Sort of. They were right in the fact that most lefties were once twins but they didn’t go far enough. Scientists now think that a ridiculous one in eight people started out as two peas in a pod. Of course, only about one in 70 people actually is a twin. So what happened to your twin? You killed it and then absorbed it into your body. Yeah, those stories of adults finding teeth in their shoulder? Not urban legends.
Why Did I Do That?!
Because you’re evil.
Not really. Chances are you were just the healthier fetus. Or you hogged all the blood if you shared a placenta. Or you grew faster and literally left your sibling no womb at the inn. If multiple pregnancies are really as common as they now seem, we evolved to be this way for a reason. Trying out two fetuses to see which one is more likely to survive is a pretty good plan evolutionarily. Unfortunately, carrying twins is very dangerous for the mother, meaning that our best bet as a species was to let one twin kill off the other early on in development. Just another reason lefties are a sinister, sinister group of people.