The logic of the ultimatum game is simple - something is better than nothing, so you ought to accept any deal where you come out ahead, no matter how unfair that deal is. Why, then, does almost everyone reject unfair deals, even if it means sacrifice?
Rejection of unfair offers in the ultimatum game is no evidence of strong reciprocity (Yamagishi et al, 2012) - https://www.pnas.org/doi/pdf/10.1073/pnas.1212126109
The tyranny of non-aggregation versus the tyranny of aggregation in social choices: A real dilemma (Fleurbaey & Tungodden, 2006) - https://core.ac.uk/download/pdf/30791273.pdf
The social and ethical consequences of a calculative mindset (Wang et al, 2012) - https://duwtje.com/wp-content/uploads/2015/06/The-social-and-ethical-consequences-of-a-calculative-mindset.pdf
Iterated Prisoners Dilemma contains strategies that dominate any evolutionary opponent (pRESS & Dyson, 2012) - https://www.pnas.org/doi/pdf/10.1073/pnas.1206569109
Fairness Versus Reason in the Ultimatum Game (Nowak et al, 2000) - https://www.jstor.org/stable/3077853
Group Decision-Making and Voting in Ultimatum Bargaining: An Experimental Study (Elbittar et al, 2011) - https://mpra.ub.uni-muenchen.de/66067/1/MPRA_paper_66067.pdf
Market Integration and Fairness: Evidence from Ultimatum, Dictator, and Public Goods Experiments in East Africa (Ensminger, 2004) - https://www.researchgate.net/profile/Jean_Ensminger/publication/51993128_Market_Integration_and_Fairness_Evidence_from_Ultimatum_Dictator_and_Public_Goods_Experiments_in_East_Africa/links/54d0d5a70cf29ca81103e86b.pdf
ULTIMATUM BARGAINING BEHAVIOR A survey and comparison of experimental results (GOTH & TIETZ, 1990) - http://www.dklevine.com/archive/refs4295.pdf
Experimental EconomicsA Philosophical Perspective (Gth & Kliemt, 2017) - https://www.oxfordhandbooks.com/view/10.1093/oxfordhb/9780199935314.001.0001/oxfordhb-9780199935314-e-16
‘Utilitarian’ judgments in sacrificial moral dilemmas do not reflect impartial concern for the greater good (Kahane et al, 2015) - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4259516/