Now this is interesting But I partially agree with the initial posts Here are some thoughts 1 If the current consensus of linguistic theory is correct there is no such thing as complex language and in fact the human language faculty as a whole has changed next to nothing in the last thousands of years So the Aboriginal in question would not be learning language as his own language differs very little structurally as well as biologically from any other human language His cultural framework is different of course but then that s an obvious almost trivial fact that is only partially connected to the language issue or at least the LI as you seem to have described it 2 As for the hard to take seriously comment I believe the criterion here is simple if you are arguing against an established scientific consensus your claims will naturally appear to be extraordinary whether you think of them as such or not And extraordinary claims demand extraordinary evidence If the evidence is not considered overwhelming in the eyes of the mainstream it s only natural that many scientists partaking of the consensus will dismiss your theory out of hand NB I m not defending knee jerk reactions but the fact is they are widespread and perhaps inevitable against all sorts of non mainstream theories whether they are plausible or not and I m sure that if Bicameralism emerged as the new consensus this would happen the other way anyway