John Henry Holland

Particular individuals do not recur, but their building blocks do.

John Henry Holland (born 2 February 1929) is an American scientist and Professor of Psychology and Professor of Electrical Engineering and Computer Science at the University of Michigan, Ann Arbor. He is a pioneer in complex systems and nonlinear science. He is known as the father of genetic algorithms.

Quotes

Hidden Order - How Adaptation Builds Complexity (1995)

Evolution continually innovates, but at each level it conserves the elements that are recombined to yield the innovations.

• "Doing science," particularly the synthesis of disparate ideas, is not as arcane as it is often made out to be. Discipline and taste play a vital role, but the activity is familiar to anyone who has made some effort to be creative.
  • Preface, p. xix

• Even though these complex systems differ in detail, the question of coherence under change is the central enigma for each.
  • Chapter 1, Basic Elements, p. 4

• With theory, we can separate fundamental characteristics from fascinating idiosyncrasies and incidental features. Theory supplies landmarks and guideposts, and we begin to know what to observe and where to act.
  • Chapter 1, Basic Elements, p. 5

• If we are to understand the interactions of a large number of agents, we must first be able to describe the capabilities of individual agents.
  • Chapter 1, Basic Elements, p. 7

• "nonlinear interactions almost always make the behavior of the aggregate more complicated than would be predicted by summing or averaging."
  • Chapter 1, Basic Elements, p. 23

• The multiplier effect is a major feature of networks and flows. It arises regardless of the particular nature of the resource, be it goods, money, or messages.
  • Chapter 1, Basic Elements, p. 25

• The recycling of resource by the aggregate behavior of a diverse array of agents is much more than the sum of the individual actions.
  • Chapter 1, Basic Elements, p. 31

• This use of building blocks to generate internal models is a pervasive feature of complex adaptive systems.
  • Chapter 1, Basic Elements, p. 37

• If there is to be a competition, there must be some basis for resolving it. It is also clear that the competition should be experienced based.
  • Chapter 2, Adaptive Systems, p. 53

• When a new building block is discovered, the result is usually a range of innovations.
  • Chapter 2, Adaptive Systems, p. 62

• Particular individuals do not recur, but their building blocks do.
  • Chapter 2, Adaptive Agents, p. 79

• Evolution continually innovates, but at each level it conserves the elements that are recombined to yield the innovations.
  • Chapter 2, Adaptive Agents, p. 80

• The measure of performance of any given agent is the amount of money it accumulates through its actions.
  • Chapter 2, Adaptive Agents, p. 86

• Looking back to data, we can see if the consequences are plausible; looking forward to theory, we can see if general principles are suggested.
  • Chapter 3, Echoing Emergence, p. 97

• There is more of a mystery to the origin of the pin factory that Adam Smith (1776) discusses in his Wealth of Nations than is generally realized.
  • Chapter 3, Echoing Emergence, p. 97

• Unwrapping occurs when the "solution" is explicitly built into the program from the start.
  • Chapter 3, Echoing Emergence, p. 137

• Model building is the art of selecting those aspects of a process that are relevant to the question being asked. As with any art, this selection is guided by taste, elegance, and metaphor; it is a matter of induction, rather than deduction. High science depends on this art.
  • Chapter 4, Simulating Echo, p. 146

• The end point, a cas simulation with a realistic interface, is highly desirable, because it enables an ecologist, or economist, or politician to try out alternatives that could not possibly tried in real systems.
  • Chapter 4, Simulating Echo, p. 158