In The Giver, why are Jonas and his father worried about Gabriel's fretfulness?

Young readers should take caution: the answer to this question is sad and disturbing.

In Chapter 6, Jonas's father has to argue before a committee to earn an additional year of care for the baby Gabriel, who wasn't gaining enough weight or sleeping well enough at night. The narrator explains, "Normally such a newchild would be labeled Inadequate and be released from the community."

What that means is that if the baby is fretful (if he doesn't sleep soundly, without fussing and crying and moving around a lot) then he might get released instead of being placed in a family.

Of course, in our world, some babies are not fretful at all, some are extremely fretful, and most are in between. We love all of them and take care of them regardless of how fretful they are, although a fretful baby's care is harder and more stressful.

Back to that chapter: we're told that "release" means that the child will leave the community forever and never be seen again. Depending on how observant we are as readers, we might already figure out right here that "release" means "death." If Gabriel is too fretful, he may be killed by the community.

Jonas knows that Gabriel's release would make his father feel unhappy, like a failure. And though Jonas himself doesn't really understand what it means to be released, he's glad that it didn't happen to Gabriel.