[pbhjpbhj]

>You would first need to establish a link between [...] then between psychology and brain structure.

You can alter psychology of a person by altering brain structure, surely that link is well established even if the finer details aren't known?

[jergosh]

You can change the way a program executes by interfering with the hardware. You can also run different programs on the same hardware.

[pbhjpbhj]

That's a link between the program and the hardware, which is the analogue of the demand that was set.

You can run the same program on different hardware, and run the same program on the same hardware and get different results. I'm not sure the analogy gets us very far.

[jergosh]

Hopefully far enough to illustrate that "altering brain structure changes personality" isn't the same as "different personalities have to have a basis in brain structure."