Is one born an introvert or is it an acquired condition?

some genetic components,, but those are often altered by Epigenitics.
AND this is something that can grow in you, depending on many factors,
including how you were raised, and in what social context.
I for one am an [b]Ambivert[/b] i have periods of both extroversion and introversion. fighting this, never worked. but adapting my life to this. has be successful.

part of my week/month i live in happy solitude, un stressed, and productive.
the other pole, is my need for intense social interactivity. and so, I pack myself off to "The World" and dive in with glee, to the realm of people

Basically, you're born with a preset, but experience can alter that preset

I think I was born one but my mother contributed to it

One is born an introvert.