Paper published in *Royal Society Open Science* and can be accessed here: https://royalsocietypublishing.org/doi/10.1098/rsos.181386 Preprints of manuscript and SI available here: https://psyarxiv.com/f5s84/ [Analysis_Main][1] provides the R code for all analyses, figures, and tables in the main paper. [SI1][2] and [SI2][3] provide R code for all supplementary analyses. [Main Data][4] provides the data used in the main paper. [Prior Social Discounting Studies][5] provides a list of all prior studies of social closeness that we reviewed, following the pre-registered inclusion criteria [here][6]. [Inconsistency in Prior Social Discounting Studies][7] provides data extracted from past studies of social discounting. The "Materials and Description" section provides experimental stimuli and protocols for all 3 sites. The "Participant Justifications Across SItes" section provides data on participants' reasons for making decisions in all 3 sites. This includes both participants' qualitative responses and our coding of those responses. The "Discount Curves from Prior Research" section contains images of the social-discounting curves from past studies. LT used these curves to extract participant generosity as a function of social distance from past studies. [Direct Replication of Social Discounting][8] provides all data, code, materials, and results from a pre-registered direct replication of a social-discounting study using online participants from Hackman, Danvers, and Hruschka (2015). [1]: https://osf.io/n35eh/ [2]: https://osf.io/tqkvj/ [3]: https://osf.io/3kghx/ [4]: https://osf.io/zkbv8/ [5]: https://osf.io/w5tur/ [6]: https://osf.io/mw37t/register/564d31db8c5e4a7c9694b2be [7]: https://osf.io/mr9gd/ [8]: https://osf.io/fn9am/