When you hear a good joke, this is the system that kicks in and produces the giggly face. - Michael S. Gazzaniga

When people talk about training, they generally mean taking an amorphous mind and shaping it into something. It is the sort of thing that goes on at universities that are not yet in possession of high-quality students. It is not the sort of thing that should go on at serious centers of discovery. Mentoring, on the other hand, is productive, necessary, and enjoyable.

Baruch Spinoza, who said, “There is no mind absolute or free will, but the mind is determined for willing this or that by a cause which is determined in its turn by another cause, and this one again by another, and so on to infinity.

The computer scientists Jeff Clune, Jean-Baptiste Mouret, and Hod Lipson did what computer scientists do: they designed computer simulations.23 They used well-studied networks that had sensory inputs and produced outputs. What those outputs were determined how well the network performed when faced with environmental problems. They simulated twenty-five thousand generations of evolution, programming in a direct selection pressure to either maximize performance alone or maximize performance and minimize connection costs. And voilà! Once wiring-cost-minimization was added, in both changing and unchanging environments, modules immediately began to appear, whereas without the stipulation of minimizing costs, they didn’t. And when the three looked at the highest-performing networks that evolved, those networks were modular. Among that group, they found that the lower the costs were, the greater the modularity that resulted. These networks also evolved much quicker — in markedly fewer generations — whether in stable or changing environments. These simulation experiments provide strong evidence that selection pressures to maximize network performance and minimize connection costs will yield networks that are significantly more modular and more evolvable.