Recommended book on emergence

After my talk yesterday about emergence and reductionism in science and theology there was some interest in learning more about the science of emergence. In my talk I recommended Bob Laughlin's book, A Different Universe: reinventing physics from the bottom down, but expressed doubt it is very accessible to non-physicists.

An alternative and more accessible book is Emergence: the connected lives of ants, brains, cities, and software by Steven Johnson.