Probably not many people’s idea of good relaxing reading, but Jerry Fodor takes on the Extended Mind Thesis in a review of Andy Clark’s Supersizing the Mind.
To oversimplify it a bit, the extended mind thesis claims that technology literally extends our minds outside of our bodies such as, for example, when we’re using a smart phone. Quoting Fodor quoting David Chalmers’ foreword to Supersizing the Mind,
I bought an iPhone. The iPhone has already taken over some of the central functions of my brain . . . The iPhone is part of my mind alrady . . . [Clark’s] marvellous book . . . defends the thesis that, in at least some of these cases the world is not serving as a mere instrument for the mind. Rather, the relevant parts of the world may have become parts of my mind. My iPhone is not my tool, or at least it is not wholly my tool. Parts of it have become parts of me . . . When parts of the environment are coupled to the brain in the right way, they become parts of the mind.
I won’t go into more detail as Fodor does an excellent job of explaining the thesis and some criticisms of it, except to note that along with technology other people would seem to also be part of the extended mind imagined by Clark and Chalmers.
For example, there is a whole class of things that rather than my smart phone I consult my wife about. Restaurant food, for example. My wife can remember exactly what I want to eat at many food establishments, whereas I don’t consider it worth my time to commit this to memory and so will interrogate the waiters about this and that food choice.
Frequently, it is just easier for me to turn to my wife and ask her what I should order since she is able to much more quickly access what it is I would like at a given place than I would. Under Clark and Chalmers formulation it would seem my wife is part of my extended mind. I haven’t read enough to know what their view on other people as part of the extended mind is, but it certainly would be an odd result if they affirm this.