Hypothesis of brain growth

The hierarchical connectivity of neurons in the neo-cortex is NOT determined at birth by a "wiring diagram" defined in our DNA. Rather, the interconnections are wired together dynamically during a child's brain development. Thus it follows the fundamental rules of self-organization of networks:

1. Growth: network grows by attaching links among it's member nodes;
2. Preferential linking: when a new link is attached, preference is given to nodes with high links;
3. Competetiveness: a more competetive node is more likely to attract new links or rewire existing links to it. Competetiveness is an intrinsic property of any node. Its effect on the ability to attract new links is likely a multiply effect.

This could explain the hierarchical connectivity among neurons, and it's scalability and robustness. What then is the key property of the neuron network that distinguishes it from the Internet, and gives rise to intelligence?