Cooperation II Flashcards
What did Robert Trivers suggest about reciprocity and cooperation?
Suggested that the actor is more likely to help recipient is they are more than repaid at a later point.
When is cooperation in the prisoner’s dilemma stable? What is the Tit-for-Tat rule? Why is this stable?
- When the interactions never end or always a chance that there will be another interaction
- That you cooperate on the first move then copy whatever the opponent did on his LAST MOVE.
- Stable because there is a future. Without a future, may as well defect.
What is an example of reciprocity in humans? How do both parties benefit? What keeps either party from “snitching”?
- Antwerp diamond market (small group of experts trade diamonds by sending them home with an expert to view and appraise)
- Individual can have diamonds appraised. Experts get business and can trade (also gain reputation points).
- If either party cheats, then they get expelled from the community. (Lose credibility)
What are the four factors that make reciprocity stable?
- Individual recognition
- Long-term associations
- Enforcement of rules
- Cost/benefits (is it worth defecting knowing future benefits?)
What is an example of reciprocity in the animal kingdom? Elaborate. What are the three reasons that this is reciprocity?
- Vampire bats
- They roost in stable groups and sometimes one comes back w/o food (1/4), so finds a buddy willing to share.
- Stable social system (long-term associations with non-related individuals)
- Benefits > Cost (buddy without food gains more than buddy giving food costs)
- Indvs. in lab feed others in same roost + increased likelihood of reciprocate help in future
What are three alternative reasons for blood sharing that aren’t reciprocity?
- Kin selection - share b/c you reside with kin
- Begging = harassment (give food to be left alone)
- Sharing leads to a bigger group which could lead to an increased chance of getting food if you don’t have any one day.
What was a study done in humans that demonstrates enforcement? What did it show?
- Coffee shop and honesty box, people pay however much they want for their coffee with pictures of either eyes or flowers. People paid 3x more with eyes than flowers.
- It showed that people pay more with the implied threat of enforcement.
How does enforcement impact elements of cooperation?
Alters cost-benefit ratio (cost of defecting becomes higher)
What are three examples of enforcement? Explain each.
- Eviction in meerkats
1a. Getting pregnant as a sub could lead to dominant evicting you (which increases stress, abortion rates, and no conceptions) (dominants want to evict b/c helpers help their offspring and don’t try to kill dom’s) - Policing in superb fairy wrens
2a. Young typically stay at the nest and help. When these birds were taken away for a period of time by experimenters ergo not helping dominants harassed them (9/14) if during breeding season (0/12 if not in breeding season). - Soybeans and nitrogen fixing bacteria
3a. If bacteria refuse to make nitrogen for the soybean, then the plants will reduce oxygen flow to the nodules (sanction oxygen)
What is manipulation?
Cooperator manipulate individuals to their benefit, but to the disadvantage of the individual doing the thing.
What are two examples of manipulation? How is the second also an example of cooperation? How do these examples differ from one another?
1a. Cuckoos and cowbirds - cuckoos lay in cowbird nests then cowbirds rear the chicks, likely losing their own offspring
1b. Lycaenidae butterfly larvae - larvae mimic ant odor so it’s thought to be an ant that is brought back to the nest (then eats ant larvae)
- Some butterfly larvae also feed ants honeydew
- The first is an example of complete manipulation while the second is not.
What is an example of a cooperation within a cooperation? What is the important bottom line in this example? How do we know that changes in behavior are due to the coop within a coop system and not due to changes with one coop?
- Larvae cooperate with ants by giving them nectar (with amino acids used for growth) in exchange for protection. Larvae cooperate with one another by clustering (decreases cost of making nectar and increases presence of ants). This also leads to a decrease in communication with the ants (eversions with tentacles).
- Cooperation between species can be manipulated by cooperation within species to decrease the overall cost.
- The alternative in this example was that the changes are driven by ant behavior. This was found untrue because if the # ants/larvae is left consistent, then these changes still occur (decrease in tentacle eversions and droplets of nectar).
What is another example of a coop within a coop (not the larvae)? Elaborate.
Seychelles warblers
. helpers are not found at every nest (used for protection and such but not breeding)
Help kin and do so based on lack of territory (or so we thought when 58 birds were removed and the helpers left).
Turns out it was due to helping their own kids (would helper males would mate with the female sometimes so they didn’t help kin, they helped to protect their own offspring). When space opened, they were able to form their own nests.
BUT! Female helpers did help kin more when helping “mom” (so directly helped their siblings).
What traits make a species good for study? (Hint: There are 4)
- Easy to study (complete and efficient data collection)
- Simple but interesting systems
- Can address deep issues related to behavior
- Insights from these species are generalizable
