https://www.cell.com/current-biology/fulltext/S0960-9822(17)31114-4?xid=PS_smithsonian
I know I’ve read a handful of things roughly a long these line, that basically it’s probably not universal that humans simplify language for infants, but that we likely do shift how we vocalize to them.
Seems like a reasonably plausible hypothesis to me.
You can vote from overseas in whatever location was your last permanent US residence.
People in DC get to vote for president because a special law was passed giving them electoral votes.
People in Puerto Rico have a US permeant residence that doesn’t let them vote for president, so they can’t legally vote from a different jurisdiction.
One of the proposals that’s come up occasionally is to make a similar law for Puerto Rico as we did for DC, but there’s never enough consensus on any plan to go forward, up until relatively recently.