I'm youngest and I do have quite a few of them traits
Carefree and fun
More wild
Don't take things too serious
Treated like the baby of the family in a way
Social
Free thinking
My oldest sibling
Reliable
Dependable
over sees things
My dh is an only and he has some of those traits
High achieving
Responsible
Perfectionist
Seeks approval
Can be a bit selfish
Good at being self entertained