These are tough questions to answer Anita.
I’m kind of vague on this I admit.
“Placid” means quiet, not seeking attention, problem free.
I have 4 older brothers. the first 3 were “normal” and I really looked up to all of them especially the intellectual one(s).
The fourth eldest brother, only a few years older than me, was disabled. He was naughty, would scream a lot,used to run away and Mom had trouble controlling him. I was well-behaved so I think a relief to her because I didn’t demand her attention. I think my parents were very concerned about my elder brother and had trouble communicating with him. (he was profoundly deaf). Eventually they sent him away to boarding school for the deaf. But then my mother was busy again having two more babies (boys) after me. My mother had 7 boys in all, a great contribution to the baby boomer era.
Honestly I feel guilty now how I have written about this. I had a happy childhood though and a lot of it was with my disabled brother, playing sports outside.