Plasticity is a property of a system that allows it to improve its efficiency by adapting to changes in its environment by altering its structure. Columbia's Eric Kandel won a Nobel Prize for showing that repeated environmental stimuli (electric shocks, etc.) lead to physical growth of neurons that dramatically alter the number of synapses, or contact points, between neighboring neurons.
This dynamic co-evolution of an organism and its environment--called epigenesis--is very important. In particular, Bruce Wexler's Brain and Culture: Neurobiology, Ideology, and Social Change details research showing that children's brains exhibit a high degree of plasticity up until about 1 years old but a dramatic loss of plasticity after that.
Essentially, children re-wire their brains to fit comfortably in the environment they see (which is why we all want to go back to our childhoods). If the environment does not change much, they will function efficiently. But if the environment changes to a dramatically different one after they lose plasticity, they experience cognitive dissonance, a permanently fearful and anxious state. Adults in this condition are not easy to get along with. They also violently resist seeing their children morph to fit the new environment. The result is conflict.The rapid change brought on by improvements in communications technology and globalization has placed many people in this state. Fundamentalism, terrorism, genocide, protectionism, immigration, and outsourcing battles all reflect its cost. But attempts to stop change are futile. The answer is finding ways to reduce its cost by reducing the frictions that transform rapid change to turbulence.
There are two primary points I wish to emphasize in relation to this material. First, progress would be greatly aided by finding effective approaches that help people cope with the disorienting aspects of rapid change. Of course they may wish to resist all change. Second, the extended order of human cooperation is like a highly plastic brain. Multitudes of new connections can be made, old connections can persist or fade rapidly as in creative destuction, but unlike a brain, the stucture of such a network is infinitely exspansible and gives rise to emergent new powers.