PSYC 205 Lecture Notes - Lecture 10: Cleaner Fish, Inclusive Fitness, Inequity Aversion
15 Jun 2018
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Week 10/Lecture 9: Prosocial Behaviour
Lecture Outline
FAQ/News
Introduction
Helping
Sharing
Comforting
Cooperation
1 Introduction
THE PUZZLE OF PROSOCIALITY
Solution 1: Be prosocial to those related to you (Kin Selection)
Reproductive Fitness: contribution to the gene pool
Made up of:
- Your own offspring
- Your relative’s offspring (because you share the same genes)
The term inclusive fitness is used
Hamilton’s Rule:
Prosocial behaviour can evolve via natural selection if the benefit of the
behaviour in relation to shared genes is greater than the costs to one’s
own reproductive success
Solution 2: Reciprocity – prosocial to people who aren’t our kin. Resources you
give are paid back in some manner
Maintaining Reciprocity
Partner Control Models
Respond to prosociality with prosociality
Respond to cheating by cheating
Use the phrase tit for tat
Way of controlling the behaviour
Partner Choice Models – you have the choice of who to interact
with
Choose prosocial partners
Respond to cheating by changing partners
Example of Partner Control and Partner Choice: Cleaner fish and their clients
(Side note: this is also an example of Inter-Specific Mutualism)
- The smaller fish cleans the bigger fish
- Small fish eats things off the bigger fish – both benefit
- Partner choice – big fish go to where little fish are seen to be
cleaning. Little fish go to big fish who are calmer
- Partner control – big fish could chase away the little fish if
caught cheating (cheating by cheating)
- Interspecific mutualism – cooccurring benefits – I help you
while you help me
o E.g humans and domestic dogs have this – dogs benefit
from food and praise. Humans benefit from help with
herding sheep, or law enforcement etc.
TYPES OF PROSOCIAL BEHAVIOUR
2 Helping
Behaviours that respond to an instrumental need
Examples:
Offspring Care and Cooperative Breeding
- Instances where there are related or unrelated adults that are
helping to rear young
- Tropical Cuckoos are unrelated and help to rear young
- Western Bluebird—related males help at the nest
Human children and chimpanzees in the laboratory
- Children help to pick up objects for strangers
o Will happen when kids are able to get up and walk
around
- Chimps – help in same situations that human toddlers are, but
with people they are comfortable with
Document Summary
Solution 1: be prosocial to those related to you (kin selection) Your relati(cid:448)e"s offspri(cid:374)g (because you share the same genes) Prosocial behaviour can evolve via natural selection if the benefit of the (cid:271)eha(cid:448)iour i(cid:374) relatio(cid:374) to shared ge(cid:374)es is greater tha(cid:374) the (cid:272)osts to o(cid:374)e"s own reproductive success. Solution 2: reciprocity proso(cid:272)ial to people (cid:449)ho are(cid:374)"t our ki(cid:374). Resour(cid:272)es you give are paid back in some manner. Partner choice models you have the choice of who to interact with. Example of partner control and partner choice: cleaner fish and their clients (side note: this is also an example of inter-specific mutualism) The smaller fish cleans the bigger fish. Small fish eats things off the bigger fish both benefit. Partner choice big fish go to where little fish are seen to be cleaning. Little fish go to big fish who are calmer. Partner control big fish could chase away the little fish if caught cheating (cheating by cheating)
