Tendency to assume that groups will make good choices automatically and to fail to manage the group decision-making process in ways that will produce better decisions. People care about fairness 1. A splits, B accepts or rejects. People will reject an unfair offer even if they gain from it. Compare a job where you get a good salary, but less than others.
People resent a hardware storethat raises prices of shovels after snowstorm.
People are social animals, and are capable of altruism, not just egoism. Neglect of fairness considerations might be an error tendency for individualists. Tendency in competitive bidding for the winner to pay too high a price. E.g. baseball teams paying highest salaries not getting their money's worth. Tendency for individuals in groups to produce riskier decisions than would the individuals alone.