I'm looking for an English (UK) idiom which I think might be similar to "I can only follow my roots" and means that I can only act in the way I was raised.
"As the twig is bent, so grows the tree." It's based on a bit of Pope:
'Tis education forms the common mind,
Just as the twig is bent the tree's inclined
The saying is used in the US. I assume, given its source, that is also used in the UK.
Similar to phrase In question one can say :
I remember my roots./I can’t [won’t] forget my roots./I remember where I came from.
Numerous examples of above online and I’m not sure if there is a clear original source. On a similar vein, I like this quote:
I remember my mother's prayers and they have always followed me. They have clung to me all my life.
Wolfgang Mieder, A Dictionary of American Proverbs (1992) identifies multiple variants of the following proverb, which may be on point:
What is bred in the bone will come out in the flesh.
Mieder says that this expression goes back to circa 1290, with a first recorded North American occurrence in 1637. The idea is that what is most deeply embedded in a person or thing will find expression closer to the surface as well.