Probably the most relevant difference is humans forming prestige hierarchies alongside dominance hierarchies with larger brains able to store more of the resulting cultural accumulation being partially downstream of that. Knowledge transmission is always imperfect but if people try to learn from the guy reputed to be the best flint napper you can support a lot more technology than if everybody just learns from their parents.
Learning from non-kin isn't unusual in the animal kingdom. Monkeys seeing other monkeys drop a mix of sand and grain in water to separate them and then copying that is a classic example. But deliberate teaching of non-kin and the way we use language to help with that teaching is pretty unique. An octopus might have smarts comparable to a feral human, but not to an acculturated human.
Learning from non-kin isn't unusual in the animal kingdom. Monkeys seeing other monkeys drop a mix of sand and grain in water to separate them and then copying that is a classic example. But deliberate teaching of non-kin and the way we use language to help with that teaching is pretty unique. An octopus might have smarts comparable to a feral human, but not to an acculturated human.