forum 10: week of March 19 - second order knowledge
I found the point about human infants and animals to be interesting because it seems that if those requirements for second order knowledge are pushed back and applied to people in the past, adults can't have it either, and then the question becomes where is the forefront of knowledge that allows for second order knowledge, and does one even exist at all.
I think the forefront that you are thinking of would be the development of meta-awareness which could be defined in different ways. According to Kelp and Pederson, children lack the ability to grasp the concept of knowledge (i.e. knowing about knowing) at a young age. Presumably this skill develops as the brain matures during early childhood. I'm no developmental psychologist but I'd guess that this skill begins to develop around age 3 or 4. I would say that adults (and children who have matured to the point of developing metacognition) can possess second-order knowledge while very young children cannot. I think the KK-principle needs some tweaking to get around this objection.