1. Game of Life Grid of binary elements, arranged on a 2-D plane, like pixels on a computer screen Each cell belongs to a neighborhood including its 8 immediate neighbors. Each cell follows simple local rules Cohesive patterns form out of apparent randomness Emergence

2. Cellular automata Very simple virtual machine that results in complex, even lifelike, behavior A cell is a bit-position on a binary string State of a cell at the next time step is determined by its state at the current time and by the states of cells in its neighborhood Simplest neighborhood includes a cell and its neighbor on either side (a neighborhood of 3)

3. Dawkins’ biomorphs Richard Dawkins, The Blind Wathmaker, and biomorphs Form was encoded in a chromosome of 9 genes, each could take values from 0 to 9. These encoded rules for the development of the biomorph, e.g. angle or length of a branch Each gene can change on step by mutation User could generate a random population, select one that looked interesting, nad use it to generate a new population, and so forth

4. Evolution Dawkins found that, though he expected his population to look like trees, he discovered that insect forms were also possible Incremental and unpredictable change in a desired direction: evolution

5. Accomplishments of Social Insects An insect may have only a few hundred brain cells (compared to hundreds of trillions of brain cells in a human), but insect organizations are capable of architectural marvels, elaborate communication systems, and terrific resistance to threats of nature A central question in the sociobiology of insects is: how does mass behavior emerge from the behaviors of single ants

6. Termites Termites build domes by thru simple rules Autocatalytic or positive feedback cycle Termite builders are a self-organizing system, there is no central control, the members of the population are unaware of the “plan” they are carrying out Stigmergy: communication by altering the state of the environment in a way that will affect the behavior of others for whom the environment is a stimulus

7. Ants Ant cemeteries Formation of piles of woodchips by termites Live ant experiment: ants find shorter path If the length is changed during the experiment, some species re-discover the shorter path and some don’t Flies trapped in a jar

8. Fish Schools Many species of fish swim in schools that seem to take on an emergent life of their own A fish school appears to move as one, with hundreds if not hundreds of thousands changing direction, darting at what appears to be the same exact instant Experiment with a solitary fish in divided tank c=kN t (e.g. k=0.355, t=0.818) Effect of t<1: sublinear increase with groupsize

9. Social Impact Latane’s experiments on social impact find that the impact of a group on an individual is a function of the Strength, Immediacy, and Number of sources of influence Nervousness of participants in a college talent show shown to be a function of number of people in audience (similar formula to fish) Do we humans exhibit herding behavior? Craig Reynolds bird flocking simulation

10. Fish Schooling Biologists have shown that fish seem to regulate their schooling behavior using visual information and information from the fish’s lateral line Vision guides the flock-centering tendency Lateral line enables collision avoiding Blinded pollock swim farther from their neighbors Fish with lateral lines removed swarm closer to their neighbors than normal fish

11. Herds and birds Possible explanation for herd-centering behavior: an animal at the edge of the herd is more likely to be picked off by a predator Biologists carried out an experiment: bird flocks were filmed with movie cameras filming at 3 frames per second. Watching these one frame at a time, they could distinguish specific features of flocking For example, there was no leader to the flock. Any bird could lead a maneuver at any time

12. Shannon’s experiments First-order: each letter is selected probabilistically based on its frequency Second-order: based on probability that letter x will be followed by letter y Third-order: based on probability that a 2- letter sequence is followed by another Experiments up to fifth order Second-order word approximation

13. Conformity and social norms Sherif placed subjects in a dark room with a point of life projected (autokinetic effect) Asch experiments: subjects asked to rate relative lengths of some lines (about a third agreed with group) Subsequent experiments: subjects in booths, so they could not see rest of group

14. Are humans herd animals? Economist Brian Arthur has noted that it is impossible for people to reason deductively in complex situations; there are just too many linkages of facts for anyone to keep them straight. People end up floundering in a pool of subjective beliefs, including subjective beliefs about subjective beliefs. The rationality that is assumed by classical economists cannot hold

15. Drunk Irishmen El Farol is a bar that has Irish music on Thursday nights Each irishman wants to go when it is not crowded; prefers not to go if more than 60 are there. Each would gladly go to El Farol, if only he knew those other noisy bastards would stay home One hundred agents set up, and each was allowed to evolve a different strategy. Result: attendance was nearly 60% over time

16. Drunk Irishmen Agents No agent dominated or performed any better on average than any others Some very sophisticated deceptive strategies had evolved Agents were allowed to report their intentions and they were allowed to lie if they wished (of course, if they lied too often, they lost credibility)

17. Conformity Another experiment: students were asked to choose one-side of a debate question to argue for Student was told he was free to choose either side, but was subtly persuaded to choose the unpopular side (while still believing he freely chose that side) Afterward the assignment was over, the student was found to have incorporated some of the beliefs of the side he had argued

18. Adaptive Culture Model Axelrod: “Agents who are similar to each other are likely to interact and become more similar Experiment: each individual is represented as a string of numerals (one might be 42237, another 99217) A matrix of individuals is initialized An individual and one of its four neighbors are selected at random

19. Adaptive Culture Model Based on flipping a biased coin (biased by degree of intersection), they interact. One individual copies one numeral from the other Sociologists say this is similar to humans, we pick up habits from those who are similar to us But, perhaps in humans, we pick up habits from those who are similar to what we would like to be (e.g. success of Seven Habits)

20. Adaptive Culture Model Experiment: optimize a simple function Experiment: Sum of first three digits equal to sum of last two Requires complex coordination of entire vector of elements Experiment: 8-city TSP. Global optimal found in 11 of 20 trials

21. Cultural Adaptation Process of cultural adaptation, at the lowest- level, includes three principles: – Evaluate your neighbors – Compare to yourself – Imitate your betters

22. Swarm Intelligence A system in which many individual agents with limited intelligence and information are able to pool resource to accomplish a goal beyond the capabilities of the individuals.

23. Particle Swarm Binary PSO Real-valued PSO Train a neural network or a fuzzy rule system No Free Lunch Theorem