Suitable English idiom for the Chinese idiom "Three years old fixes eighty" (三歲定八十)
Solution 1:
According to the Oxford Dictionary of Phrase and Fable,
As the twig is bent, so is the tree inclined.
as the poet Alexander Pope wrote around 1732, means early influences have a permanent effect.
Solution 2:
"The child is the father of the man" does fit here.
- "Every man was once a child, and his character has developed from his character as a child. In the same way his body has developed from the child's body, so in two ways the child can be called "father of the man"." A. Johnson, Common English Proverbs