Do they understand and actually bona fide engage in trolling?
If not linguistically than in what they do?
I’d call it “teasing” or “play” rather than “trolling”. Trolling has a bit of a mean connotation to it where as teasing/play is more, well, playful.
But, yes, after a certain point babies/infants do understand teasing play. That’s essentially what games like peek-a-boo are. Babies don’t have real object permanence until they’re 8-12 months. That is, they don’t fully have the ability to recognize that a thing still exists when it is not within their site/sensory perception until they’re 8-12 months. (It gradually develops, so they’ll gain more and more object permanence as they get older rather than just turning on all of a sudden.) When you play peek-a-boo, you’re using this lack of fully developed object permanence to tease them. They won’t recognize it as teasing at first, but they get it pretty quickly. That’s why they laugh and have fun with it.
I get screamed at for attention sometimes, which seems like a pretty good definition of trolling. So yeah.
What do you mean by “trolling”? It’s not like that’s a word that has a consistently agreed-upon definition.
I mean kind of like they act out knowing it gets a reaction and they have some enjoyment in seeing that process play out
Depending on the age, they do it on purpose. Sometimes it’s because they are just figuring out social situations – doing X to person Y results in action Z.
You can find videos of babies pretending to be stuck and crying to get attention. When “unstuck” and not given attention, they stop crying, get themselves fake-stuck again and start crying again. They want the attention and coddling that they got the last time they were legitimately stuck.
I’m sure some babies know they’re faking it.