Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bursts of cooperation triggered by external stimuli in violent and other
  uncertain situations   Individuals are reluctant to cooperate for public goods if others freeride on
their efforts. Cooperation can be fostered by mechanisms that make benefits
exceed costs, such as norms with sanctions, but these take time to develop and
may be ineffective for impromptu challenges such as defense against or defeat
of opponents. Nevertheless, cooperation can be triggered by situational
stimuli, for example the sight of victims or provocations by opponents. An
Ising spinglass model demonstrates that at a critical level of stimuli, few
accidental cooperators entail a burst of cooperation among the rest. If the
proportion of defectors is above the critical threshold, however, bursts do not
occur, and only a few group members cooperate. The distinction between bursts
and fizzles is strongly supported by video data of street violence. Ultimately,
the model is generalized by incorporating the usual mechanisms, and can then
explain cooperation without stimuli.

30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio