Cooperation, Altruism, and Self-control

非技术总结：合作、利他主义和自我控制合作是人类和动物社会行为的关键组成部分。研究动物行为的科学家借鉴了经济博弈论的思想来研究动物合作的进化和维持。博弈论家研究的最简单的游戏类型是“2人2乘2游戏”，在这种游戏中，两名参与者必须从两种行动中选择一种。本研究使用2乘2博弈作为实验和理论工具来理解动物合作的经济和进化基础。通过将研究限制在2乘2的游戏中，研究者可以简化和分类可能的“合作”情境。合作可能是“自私的”，即短期内对双方都有利的最佳行为，也可能是“利他的”，即牺牲短期利益的良好长期行为。利他主义被认为是行为进化研究中的一个核心问题，因为自然选择的过程被认为从根本上是竞争性的。实验研究表明，动物很少会无私地合作。一种解释这一事实的假说是，动物对即时奖励有强烈的、有据可查的偏好。用心理学术语来说，他们往往无法表现出必要的“自我控制”来等待一个好的但延迟的奖励。本研究由一系列实验组成，在这些实验中，研究者将操纵明确行动的成本和收益。其中一项实验将比较三种鸟类的合作能力：鸦群中高度群居的小冠鸦、鸦群中非群居的冠蓝鸦和欧椋鸟，一种不相关的群居鸟。在一项平行研究中，研究者将测量每个物种对即时奖励的偏好程度。然后，研究者将询问这些物种在合作倾向上是否存在差异，以及这些差异是否与它们对即时性的偏好有关。第二个实验将检验利他合作数学模型的基本主张。数学建模者认为，2乘2博弈的重复与“互惠合作”策略的结合，可以使利他合作成为一种良好的短期行为。第三个实验将检验研究者的假设，即对即时性的强烈偏好解释了在实验室环境中观察到的动物无法无私合作的现象。

Non-technical Summary: Cooperation, Altruism and Self-Control P.I. David W. Stephens IBN- 9507668 Cooperation is a key component of human and animal social behavior. Scientists who study animal behavior have borrowed ideas from economic game theory to study the evolution and maintenance of animal cooperation. The simplest category of games studied by game theorists is "Two-player, 2-by-2 games" in which each of two participants must choose one of two actions. This study uses 2-by-2 games as an experimental and theoretical tool to understand the economic and evolutionary underpinnings of animal cooperation. By restricting this study to 2-by-2 games, the investigator can simplify and categorize the range of possible "cooperative" situations. Cooperation may be either "selfish," the best action in the short-term for both participants, or "altruistic," a good long-term action that sacrifices short-terms gains. Altruism is considered a central problem in evolutionary studies of behavior, because the process of natural selection is thought to be fundamentally competitive. Experimental studies suggest that animals seldom cooperate altruistically. One hypothesis explaining this fact is that animals have strong and well- documented preferences for immediate reward. In psychological jargon, they often fail to show the required "self-control" to wait for a good but delayed reward. This study is composed a series of experiments in which the investigator will manipulate the costs and benefits of well- defined actions. One experiment will compare the cooperative abilities of three specis of bird, the pinon jay, a highly social member of the crow group, the bluejay, a non-social member of the crow group ,and the european starling, an unrelated gregarious bird. In a parallel study the investigator will measure the strength of each species' preferences for imediate reward. The investigator will then ask whether the species differ in their tendencies to cooperation, and whether these differences correlate with their measured preferences for immediacy. A second experiment will test a basic claim of mathematical models of altruistic cooperaion. Mathematical modelers have argued that the combination of repetition of a 2-by-2 game, and a strategy of "reciprocal cooperation" can make altruistic cooperation a good short-term action. A third experiment will test the investigator's hypothesis that strong preferences for immediacy explain the observed failure of animals to cooperate altruistically in laboratory situations.