There are two types of twins. One is hereditary and the other chance. Fraternal twins are twins that run in families. These twins occur because two separate eggs have dropped in the same month and were fertilized though not necessarily at the same time. The children who are fraternal twins are as alike as two separate siblings from the same mother and father. They don’t even have to be the same sex.
The other type of twin is called an identical twin because it is created by chance when the egg splits into two at fertilization, creating separate embryos. These identical twins tend to look almost the same. They are same sexed and are closer DNA matches to each other than to any other sibling from the same parents.
Identical twins are very close but are not the same people. They develop just as all babies do. Like fraternal twins they aren’t the same emotionally or even intellectually. They are their own person. Identical twins do however share in a higher instance of some form of autism. While one twin will be high functioning, even to what is considered normal, the second twin is always on a lower more autistic symptom level. We will get to that next time.