I believe that it is hereditary but if there's a way for a couple to boost their cells or eggs to have that chance of getting a twin then I don't know about science since I didn't studied that.
Much better for those that have read this and wanting to try then it's always best to the medical professionals or doctors that are majoring into this kind of studies and cases.
Like yours I believe this is hereditary because if this can be treated to become successful
then rich family can have their own set of twins but it is not that easy to turn into reality..
My grandma has her twin sister but none of us till my generation that has a twin coming from birth.
I think that they can have some modification through genes through science but it comes with a hefty cost.
That's a good argument and indeed I have read some news about that and yeah
its my mistake saying it is impossible yet you need to be rich just to have a dream twins.
But mainly, this is like a gift from nature and it is hereditary. I haven't looked yet with the studies that have successfully modified it with couples that have no history and background of having twins in their family.
or maybe those who don't know their long bloodlines that have no complete idea that
their genes runs from older generations in which they have a twins.