Well "experiment" always depends from which point of view you're looking at it... Concerning the steps of our human type there are told to be 5 types (or was it four?)...
The first one is a bit smaller than us and it still has the consciousness of the "collective mind" or how you want to call it. The Aborigines most certainly are the only "humans" of that kind left on earth and if you read some stories about them you'll probably hear about that if one of them experiences something the other ones can sort of go into that experience in a dream like manner. This also makes former cultures of that type extremely hard to verify as they e.g. don't need to write anything down as they can enter that collective consciousness. For other examples for the concept of such a central consciousness e.g. look up the "100th ape" phenomenom. There also have been some studies to prove such a thing for us humans leading to an experiment (repeated for several hundred times now afaik) being focused around a test people have to write. The same test gets written several times by different people. Amazingly when you average the results the groups writing them later on always had higher scores. This then was proven to be a general behaviour when repeating it with different tests and people writing them. That's a big hint of some sort of interconnection between every human making it "easier" to solve problems others have thought about before. The result of course is limited meaning you just could get a certain improvement over the first groups which didn't really go up when doing it again and again...
The second one is us. We're a bit taller than the first type and certainly a bit more intelligent. We've lost all contact to the central consciousness as well as for anything else and just are aware of our physical body...
The third type again is a big tad taller when we and it again has a consciousness of many things apart from the physical body. It most certainly again is a bit more intelligent than us - i.e. has the potential for that...
The fourth type then is "ridiculously" tall. Actually some of those statues from egypt actually show people of that size. There e.g. is one statue of a pharao of that size and sort of at the edge of the throne he sits on there is a woman (the "queen") which has a pretty much a height a tall woman of our type would have. Officially nobody has a clue as to why it was done that way which is why it is said that the pharao was way more "important" which is why they made him that big and the queen just that small. It's a remain of those advanced humans ruling / teaching us though. For the same reason you won't just find quite some statues of that size but also hallways and buildings built with huge heights and doorsizes simply to make them "fit" comfortably in there. You can't really explain that by a wanted "pomposity" as it would make not too much sense / it'd be hard to explain why no other culture like e.g. the Romans built their stuff in such a style (i.e. everything in a way that it's designed for a really tall human)...
I'm not too sure if that was the final type or not right now. There might have been a fifth type as I still remember that it's said to have a blueish skin and I know of one reported being who fits that which would be Metatron...
