Personality types are linked with structural differences in the brain - which could explain why one child grows up to be impulsive and outgoing while another becomes diligent and introspective

wow!

so if one is not born with the 'persistence' traits, one can't achieve these in any othe rway - as tehre are even different btain structures-? not very happy learning this....

they suggest that children are not only born with a given personality
type, but they develop anatomically different brains as a result of
being that sort of person

Interesting. I know some people who I feel might greatly benefit from a personality transplant

I believe it goes even deeper. The basic personality is formed in the womb through the DNA structure. Just as hair-color, eye-color, body shapes, etc...are inherited so also would basic personality traits. However, our personalities can be influenced and changed somewhat with life experiences.

Sometimes claims like this could lead a person to use these studies as an excuse for unacceptable behavior.

"our personalities can be influenced and changed somewhat with life experiences". I'm going to go with "are influenced" and "can be changed dramatically".