Life sciences · the experiment
Light the campfire school
A group of hunters, a norm that says when to stop hunting and train the young, game shared by everyone. Find the group size at which teaching starts to pay, with no family ties at all.
1 · Grow the group
Beginner
In the model, can a norm of retiring to teach win out among people with no family ties at all?
Parameters of the paper's Figure 2. Find the smallest group size for which a retirement norm yields more game over a lifetime than no retirement.
2 · Count the teachers
At equilibrium, the share of teachers is r/(r + d_T), where r is the retirement rate and d_T the teachers' death rate. It is also the share of their life each person spends retired.
Intermediate
With r = 0.05 and d_T = 0.2, what share of their life does each person spend retired?
3 · Let the elders live longer
The critical size is (1 + d_T/d_H) times the size at which teaching merely becomes useful. Here, teachers die four times faster than hunters: d_T = 0.2 against d_H = 0.05. Thanks to elder care, they would now live just as long: d_T = 0.05.
Expert
What happens to the critical size?
Check it: with d_T = 0.05, find the new smallest group size.
4 · Launch three pioneers
A group of 1,000 people lives without teachers, well above the critical size. Three of them adopt a norm of retiring to teach.
Expert
Can their norm win out?
School lit
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