Evolutionary modeling of behaviour in sociobiology and psychology

有两个项目，都是对行为的进化研究。第一个属于生物学，涉及我们在试图理解生物体行为时所使用的理论结构的性质和结构。第二种方法更多地属于心理学和经济学，既有理论成分，也有实验成分。它使用了一个新的“信号”版本的最后通牒游戏，以帮助我们了解人类在经济决策中的行为。项目1继续我正在进行的研究的包容性健身（IF）的方法来分析社会行为。这涉及行为者的行为影响亲属健康的情况，人们长期以来一直认识到，选择性的力量应该改变行为，以考虑到这种影响。汉密尔顿（F8）表明，进化应该最大化这些适应性效应的简单加权（通过相关性）和。这种结构的IF效应是简单和直观的（帮助你的邻居与他们的“亲密度”成比例），在一系列广泛的假设下（主要是弱选择），它的预测与更详细的遗传模型相匹配。我过去的工作是讨论IF模型的预测，并建立精确的等价结果，以其他标准的适应性措施，如固定概率。在这项工作中，我发现了许多优雅的结构结果。这些包括两个进化稳定的一般条件;第一个适用于所有同质群体结构（F25），第二个适用于有限和无限群体（CCV 10）的协同（非加性）适应性效应。这是肯定的情况下，如果制定是至关重要的发现这些简单的conditions. In未来五年我将继续这项工作，寻求简单的一般结果，重点放在类结构的人口和非加性健身效果。在项目2的最后通牒博弈中，参与人1向参与人2提出如何分割可用资源的提议，但只有参与人2接受才能实现;否则双方都得不到任何东西。实验表明，人类在玩这个游戏时比纳什均衡预测的要慷慨得多。在我们的变体中，参与人2提出了一个预先的要求：“我接受不少于x”，然而，他并没有被迫遵守。这类似于雄性黑鹂翅膀上的红色斑块，似乎是良好的父子关系，但可能是不诚实的。这个可能是空的需求如何影响1号博弈者的出价呢？从生物学研究中可知，这种质量信号不起作用，除非它们对信号发送者收取成本，因此，我们引入并研究了与需求和“minaccept”之间的差异成比例的成本，低于该值，报价将失败。这个项目激发了我格拉德生的兴趣，我将能够让他们参与模型的构建以及实地工作。

There are two projects, both evolutionary studies of behaviour. The first belongs to biology and concerns the nature and structure of the theoretical constructs we use in our attempt to understand behaviour of living organisms. The second belongs more to psychology and economics and has both theoretical and experimental components. It uses a new “signal” version of the much studied ultimatum game to help us understand human behaviour in economic decision making. Project 1 continues my ongoing study of the inclusive fitness (IF) method for analyzing social behaviour. This concerns situations in which the behaviour of an actor affects the fitness of relatives and it has been realized for a long time that selective forces should modify behaviour to take account of such effects. Hamilton (F8) showed that evolution should maximize a simple weighted (by relatedness) sum of these fitness effects. This constructthe IF effectis simple and intuitive (help your neighbours in proportion to their “closeness”) and under a wide set of assumptions (principally weak selection) its predictions match those of more-detailed genetic models. My past work has been to discuss the predictions of IF models and establish precise equivalence results to other standard measures of fitness such as fixation probability. In this work I have discovered many elegant structural results. These include two general conditions for evolutionary stability; the first applies to all homogeneous population structures (F25) and the second to synergistic (non-additive) fitness effects in both finite and infinite populations (CCV10). It is certainly the case that the IF formulation was crucial to the discovery of these simple conditions.Over the next five years I will continue this work, seeking simple general results, focusing on class-structured populations and non-additive fitness effects. In the ultimatum game of Project 2, player 1 makes an offer to player 2 of how to split an available resource, but that is implemented only if player 2 accepts; otherwise both get nothing. Experiments show that humans play this game much more generously than the Nash equilibrium would predict. In our variation, player 2 makes an up-front demand: “I will accept no less than x,” which, however, he is not compelled to adhere to. This is analogous to the red patch on a male blackbird wing that appears to signal good paternity but might be dishonest. How is this, possibly empty, demand to affect player 1's offer? It is known from biological studies that such signals of quality do not work unless they exact a cost on the signaler and for this reason we introduce and investigate a cost taken to be proportional to the difference between the demand and the “minaccept” below which the offer will fail. This project has inspired the interest of my grad students and I will be able to involve them in the model building as well as the field work.