If you've raised a kid, a lot of these things are really obvious with just a few gaps of understanding here and there where a good book on learning comes in handy. Watching a tiny human go from knowing virtually nothing more than how to breathe, three years later, singing, ABCs, various animal recognition and a plethora of other stuff is educational to understanding "learning". If you haven't raised a kid, then it's no harm, no foul. I didn't realize how important family influence was on a child's learning until I did it myself.

I think you're working too hard with the semantics here. Parents, as in, who ever the hell takes care of the kid the most. That's either your bio-parents, typically. Maybe grandparents if your bios are crackheads. Maybe a foster care system because everyone in your family is jacked up in general. But parent: those that are responsible for your general well being. Yes "society" plays a roll. But random people don't walk up to a toddler to teach them their ABCs or 123s. Someone has to work with a kid from beginning to end for that developmental knowledge foundation or that kid has a really good chance of having a ton of problems down the line. And yes, schools still do the ABCs and numbers. But that's more to fill gaps, which do happen. Not to straight up teach a kid that can't do shit at all. There are different programs for when a 5 year old can't even say their own name. Research shows things like consistent night time reading and playing with infants and toddlers give them a solid base that proves them well throughout their lives. There was one paper (out of many) that was on hackernews a week or two ago about it as well.

And technically elephants do communicate, both vocally and through body language. As do most mammals. Just no where near the sophistication we can. That has to do with the sophistication of the brain. Those crazy folks that have wolf sanctuaries and are "apart of the pack", would argue with you about animal language too. But to be fair, you have to be a level of crazy of jump into a cage full of wolves. Hell, bees do interpretive dance to communicate. They sure kick my ass in that field. Then take Koko. From the age of 1, they taught a guerrilla to use a modified form of American sign language and was pretty proficient at communicating. I highly doubt starting at a later age would have been as effective. Developmental years of learning are vital for that foundation.