Abstract
The purpose of this research is to explain the force of homophily and in-group bias that involve some degree of discrimination towards others, in the context of the pension game, a transfer-making setting where mutual transfers are efficient, but transfers are individually costly. We study reciprocity, in-group bias and homophily experimentally using three scenarios; first, all participants are identical, second, participants are assigned randomly to two artificial groups, and third, participants can affect their likelihood to be matched with a participant of the same group in an endogenous matching scenario. The second and third scenarios are designed to measure the effects of group identity and group preference on transfer decisions. Although numerous studies exist on reciprocity and lately homophily, the experimental setup introduces a sequential matching structure relevant in many social transfer settings, such as pension savings. Results show that participants behaved differently in different matching structures, homophily, and in-group bias affect the maintenance of a cooperative outcome. In the case of sequential transfers, participants have transferred nearly 40% more in in-group transfers compared with out-group transfers. Regarding reciprocity, in random matchings, we see that there is higher reciprocity in out-group matches compared with in-group matches, meaning higher rewards together with higher sanctions in out-group transfers, but when we allow for preferential matchings, reciprocal behaviour is replaced with an inclination to control the similarity of partners.
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Data availability
The data that support the findings of this study are available upon request from the corresponding author, [B.O.G.].
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This research was supported by the Galatasaray University Scientific Research Programme (GSU BAP), under grant number FBA-2020-1011.
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BOG and EOY have contributed equally to the manuscript.
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This research was conducted in accordance with the principles of the Declaration of Helsinki. The experimental protocol was reviewed and approved by the Ethics Committee of Galatasaray University (Decision Number: 2392). Approval was granted on 16 March 2020. All experimental procedures were performed in strict adherence to the guidelines and regulations established by the approving committee.
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Informed consent was obtained from all participants involved in the study via an electronic consent interface. Before participating in the online experiment, all individuals were presented with information detailing the study’s objectives, the voluntary nature of participation, and the guaranteed anonymity of the collected data. Participants were required to actively select a “consent” checkbox to confirm they had read the information and agreed to take part before they could proceed to the tasks. Data collection took place online between May 5, 2020, and May 4, 2022. This process ensured that informed consent was documented for every respondent. No personally identifiable information was stored, ensuring the full confidentiality of all participants.
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Öztürk Göktuna, B., Yurdakurban, E.Ö. Homophily and in-group bias in pension game. Humanit Soc Sci Commun (2026). https://doi.org/10.1057/s41599-026-06744-9
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DOI: https://doi.org/10.1057/s41599-026-06744-9
