It's an interesting question, but maybe more complex than it appears. We cannot get rid of the cultural passing of information (non-genetic) in humans. If we do, we get feral children [1] (also known as Mowgli in popular culture). But I doubt anyone would seriously want to compare this "pure" intelligence with that of other primates. There is a possible agreement that socialization is not an option for humans but a requirement. Maybe if by some bad luck feral children were grouped together for some time, this might be an approximation, but I'm not sure. Overall, using computers as an analogy, it's like humans are only functional after the software installation following the first power-on, which is more or less required for normal activity.
This may not be entirely accurate. Feral children are those that do not have interaction with other humans.
If you had a bunch of human children together and provided them sustenance and all that without adult interaction they might still develop normally and form their own language and means of communication with each other.
We don’t know for sure because such an experiment would be horrible and extremely immoral. However I do remember reading a while back that a similar situation happened where a bunch of deaf children in a an environment without much adult interaction did manage to create their own sign language to communicate with each other.
So it seems the feral child phenomena might be due to the fact that the child is alone rather than simply due to the child not having adult interaction.
> where a bunch of deaf children in a an environment without much adult interaction did manage to create their own sign language
You probably had Nicaraguan Sign Language [1] in mind. I think it’s a good example of the human brain’s ability to invent something and acquire knowledge easily. What I tried to show with my comment is that when human intelligence is discussed, it’s easy to refer to all instances of human achievements around us, but they are essentially accumulated cultural knowledge. Because of this, we tend to overestimate our intelligence, at least when comparing an individual human with an individual primate of another kind.
So, it’s also interesting why humans are probably unique in this ability to pass on and accumulate information, while other apes (and crows) limit this to skills like retrieving ants with sticks and breaking shells with stones.
[1] https://en.wikipedia.org/wiki/Feral_child