---
_id: '9997'
abstract:
- lang: eng
  text: Indirect reciprocity is a mechanism for the evolution of cooperation based
    on social norms. This mechanism requires that individuals in a population observe
    and judge each other’s behaviors. Individuals with a good reputation are more
    likely to receive help from others. Previous work suggests that indirect reciprocity
    is only effective when all relevant information is reliable and publicly available.
    Otherwise, individuals may disagree on how to assess others, even if they all
    apply the same social norm. Such disagreements can lead to a breakdown of cooperation.
    Here we explore whether the predominantly studied ‘leading eight’ social norms
    of indirect reciprocity can be made more robust by equipping them with an element
    of generosity. To this end, we distinguish between two kinds of generosity. According
    to assessment generosity, individuals occasionally assign a good reputation to
    group members who would usually be regarded as bad. According to action generosity,
    individuals occasionally cooperate with group members with whom they would usually
    defect. Using individual-based simulations, we show that the two kinds of generosity
    have a very different effect on the resulting reputation dynamics. Assessment
    generosity tends to add to the overall noise and allows defectors to invade. In
    contrast, a limited amount of action generosity can be beneficial in a few cases.
    However, even when action generosity is beneficial, the respective simulations
    do not result in full cooperation. Our results suggest that while generosity can
    favor cooperation when individuals use the most simple strategies of reciprocity,
    it is disadvantageous when individuals use more complex social norms.
acknowledgement: 'This work was supported by the European Research Council CoG 863818
  (ForM-SMArt) (to K.C.) and the European Research Council Starting Grant 850529:
  E-DIRECT (to C.H.). L.S. received additional partial support by the Austrian Science
  Fund (FWF) under Grant Z211-N23 (Wittgenstein Award).'
article_number: '17443'
article_processing_charge: Yes
article_type: original
author:
- first_name: Laura
  full_name: Schmid, Laura
  id: 38B437DE-F248-11E8-B48F-1D18A9856A87
  last_name: Schmid
  orcid: 0000-0002-6978-7329
- first_name: Pouya
  full_name: Shati, Pouya
  last_name: Shati
- first_name: Christian
  full_name: Hilbe, Christian
  last_name: Hilbe
- first_name: Krishnendu
  full_name: Chatterjee, Krishnendu
  id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87
  last_name: Chatterjee
  orcid: 0000-0002-4561-241X
citation:
  ama: Schmid L, Shati P, Hilbe C, Chatterjee K. The evolution of indirect reciprocity
    under action and assessment generosity. <i>Scientific Reports</i>. 2021;11(1).
    doi:<a href="https://doi.org/10.1038/s41598-021-96932-1">10.1038/s41598-021-96932-1</a>
  apa: Schmid, L., Shati, P., Hilbe, C., &#38; Chatterjee, K. (2021). The evolution
    of indirect reciprocity under action and assessment generosity. <i>Scientific
    Reports</i>. Springer Nature. <a href="https://doi.org/10.1038/s41598-021-96932-1">https://doi.org/10.1038/s41598-021-96932-1</a>
  chicago: Schmid, Laura, Pouya Shati, Christian Hilbe, and Krishnendu Chatterjee.
    “The Evolution of Indirect Reciprocity under Action and Assessment Generosity.”
    <i>Scientific Reports</i>. Springer Nature, 2021. <a href="https://doi.org/10.1038/s41598-021-96932-1">https://doi.org/10.1038/s41598-021-96932-1</a>.
  ieee: L. Schmid, P. Shati, C. Hilbe, and K. Chatterjee, “The evolution of indirect
    reciprocity under action and assessment generosity,” <i>Scientific Reports</i>,
    vol. 11, no. 1. Springer Nature, 2021.
  ista: Schmid L, Shati P, Hilbe C, Chatterjee K. 2021. The evolution of indirect
    reciprocity under action and assessment generosity. Scientific Reports. 11(1),
    17443.
  mla: Schmid, Laura, et al. “The Evolution of Indirect Reciprocity under Action and
    Assessment Generosity.” <i>Scientific Reports</i>, vol. 11, no. 1, 17443, Springer
    Nature, 2021, doi:<a href="https://doi.org/10.1038/s41598-021-96932-1">10.1038/s41598-021-96932-1</a>.
  short: L. Schmid, P. Shati, C. Hilbe, K. Chatterjee, Scientific Reports 11 (2021).
corr_author: '1'
date_created: 2021-09-11T16:22:02Z
date_published: 2021-08-31T00:00:00Z
date_updated: 2026-05-14T22:30:45Z
day: '31'
ddc:
- '003'
department:
- _id: GradSch
- _id: KrCh
doi: 10.1038/s41598-021-96932-1
ec_funded: 1
external_id:
  isi:
  - '000692406400018'
  pmid:
  - '34465830'
file:
- access_level: open_access
  checksum: 19df8816cf958b272b85841565c73182
  content_type: application/pdf
  creator: cchlebak
  date_created: 2021-09-13T10:31:21Z
  date_updated: 2021-09-13T10:31:21Z
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file_date_updated: 2021-09-13T10:31:21Z
has_accepted_license: '1'
intvolume: '        11'
isi: 1
issue: '1'
keyword:
- Multidisciplinary
language:
- iso: eng
month: '08'
oa: 1
oa_version: Published Version
pmid: 1
project:
- _id: 0599E47C-7A3F-11EA-A408-12923DDC885E
  call_identifier: H2020
  grant_number: '863818'
  name: 'Formal Methods for Stochastic Models: Algorithms and Applications'
- _id: 25F42A32-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: Z211
  name: Formal methods for the design and analysis of complex systems
publication: Scientific Reports
publication_identifier:
  eissn:
  - 2045-2322
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
related_material:
  record:
  - id: '10293'
    relation: dissertation_contains
    status: public
scopus_import: '1'
status: public
title: The evolution of indirect reciprocity under action and assessment generosity
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 11
year: '2021'
...