1 / 46

The evolution of cooperation

The evolution of cooperation. Altruism and the selfish gene. Altruism: benefit b to recipient at cost -c to the donor. Altruism and the selfish gene. Altruism: benefit b to recipient at cost -c to the donor `get the altruism out of altruism...´ (Trivers). Altruism and the selfish gene.

sanne
Download Presentation

The evolution of cooperation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The evolution of cooperation

  2. Altruism and the selfish gene • Altruism: benefit b to recipient at cost -c to the donor

  3. Altruism and the selfish gene • Altruism: benefit b to recipient at cost -c to the donor • `get the altruism out of altruism...´ (Trivers)

  4. Altruism and the selfish gene • Altruism: benefit b to recipient at cost -c to the donor • `get the altruism out of altruism...´ (Trivers) • kin selection • Hamilton´s rule: c< b.r

  5. Altruism and the selfish gene • Altruism: benefit b to recipient at cost -c to the donor • `get the altruism out of altruism...´ (Trivers) • kin selection • Hamilton´s rule: c< b.r • in humans co-operation among non-relatives

  6. Darwin: • The small strength and speed of man, his want of natural weapons, etc., are more than counterbalanced ... by his social qualities, which led him to give and receive aid from his fellow men.

  7. Cooperation among non-relatives • Direct reciprocation and the Prisoner´s Dilemma • Indirect reciprocation • Public Goods

  8. Consequently, theories of evolution which, in accordance with the philosophies inspiring them, consider the mind as emerging from the forces of living matter, or as a mere epiphenomenon of this matter, are incompatible with the truth about man. Nor are they able to ground the dignity of the person.

  9. Reciprocity • Reciprocal altruism...the trading of altruistic acts in which benefit is larger than cost, so that over a period of time both parties enjoy a net gain. • (Trivers)

  10. The Prisoner´s Dilemma game • To cooperate or to defect • (example: cooperate means to give a gift of value b at cost -c)

  11. Prisoner´s Dilemma

  12. Prisoner´s Dilemma

  13. The iterated Prisoner´s Dilemma • probability w for another round • (for instance, toss a coin, stop game if 6) • shadow of the future (Axelrod)

  14. The iterated Prisoner´s Dilemma

  15. The iterated Prisoner´s Dilemma

  16. The iterated Prisoner´s Dilemma

  17. The iterated Prisoner´s Dilemma

  18. The iterated Prisoner´s Dilemma

  19. The iterated Prisoner´s Dilemma

  20. The iterated Prisoner´s Dilemma

  21. The iterated Prisoner´s Dilemma

  22. The iterated Prisoner´s Dilemma

  23. The iterated Prisoner´s Dilemma • Generous Tit For Tat • p close to 1 • q sizeable • two zones

  24. The iterated Prisoner´s Dilemma

  25. The iterated Prisoner´s Dilemma

  26. The iterated Prisoner´s Dilemma • Heteroclinic network • A = Tit or Tat • B = Firm But Fair • C = Bully • D = AllD

  27. The iterated Prisoner´s Dilemma

  28. The iterated Prisoner´s Dilemma

  29. Pavlov • Cooperate if other player used same move as yourself in previous round • reinforcement principle: repeat former move after high payoff • Pavlov is error-correcting • Pavlov is stable • Pavlov cannot invade population of defectors

  30. Pavlov

  31. Pavlov

  32. Pavlov

  33. Pavlov • Simple learning rule • stable, error-correcting • but needs retaliator to prepare the ground

  34. Indirect reciprocity • few rounds, as donor or receiver • never with the same partner twice

  35. Indirect reciprocity • R. Alexander: • Indirect reciprocity .. involves reputation and status, and results in everyone in the group continually being assessed and reassessed.

  36. Indirect reciprocity • R. Alexander: • Indirect reciprocity .. involves reputation and status, and results in everyone in the group continually being assessed and reassessed. • Cooperation channelled towards cooperative members

  37. Indirect reciprocity • score: increases by 1 if help is given, decreases by 1 if help is withheld • score 0 at birth

  38. Indirect reciprocity • score: increases by 1 if help is given, decreases by 1 if help is withheld • score 0 at birth • strategy k: give only if recipient has score at least k • k>5: always defect • k<-5: always help

  39. Indirect reciprocity

  40. Indirect reciprocity

  41. Indirect reciprocity • cooperation based on discrimination • but not stable (can occasionally break down)

  42. Indirect reciprocity

  43. Indirect Reciprocity

  44. William D. Hamilton • The theory of many-person games may • seem to stand to that of two-person games • in the relation • of sea-sickness to a head-ache!

More Related