Yes, I am sure.
It measures the balance between Life and Neutral. Or L1 and L2 and Neutral if you have a 2-phase split US 240V dryer socket. Or L1,L2,L3,N if you have a 3-phase system.
In all cases, if those currents do not balance out, it trips. It does not actually need to measure if any current goes through ground. And thats a good thing to, because if you touch any hot wire, current would flow through you into the real ground, and not back through the ground wire.
It is indeed needed to have Neutral and Ground connected to have the GF device work, but that connection can be (and will be) all the way in the nearest power company owned trasformer. No actual ground wire needed in your premises. There are other reasons why you should have a ground wire, but not to make the GF device work.
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Proper names are RCD in UK, or CFCI in US. Or ALCI or RCCB. And then you have the combined overload protection ones RCBO. They are called Alamat in NL. Who knows what they are called in Brazil.
Also, while I will not try it, I firmly believe that if you "stick your hand between" life and neutral, it is very unlikely the current will stay balanced, therefore it will trip. So while not designed for it, with great likelihood it will also protect against grabbing both wires. It will be a bigger burn due to the short path between wires, so don't try. But it will probably trip. (unless if you are also standing on a rubber plate)