Simulation Models of the Evolution of Cooperation as Proofs of Logical Possibilities. How Useful Are They?

This paper discusses critically what simulation models of the evolution of cooperation can possibly prove by examining Axelrod’s “Evolution of Cooperation” (1984) and the modeling tradition it has inspired. Hardly any of the many simulation models in this tradition have been applicable empirically. Axelrod’s role model suggested a research design that seemingly allowed to draw general conclusions from simulation models even if the mechanisms that drive the simulation could not be identified empirically. But this research design was fundamentally flawed. At best such simulations can claim to prove logical possibilities, i.e. they prove that certain phenomena are possible as the consequence of the modeling assumptions built into the simulation, but not that they are possible or can be expected to occur in reality. I suggest several requirements under which proofs of logical possibilities can nevertheless be considered useful. Sadly, most Axelrod-style simulations do not meet these requirements. It would be better not to use this kind of simulations at all

When can a Computer Simulation act as Substitute for an Experiment? A Case-Study from Chemisty

In this paper we investigate with a case study from chemistry under what conditions a simulation can serve as a surrogate for an experiment. The case-study concerns a simulation of H2-formation in outer space. We find that in this case the simulation can act as a surrogate for an experiment, because there exists comprehensive theoretical background knowledge in form of quantum mechanics about the range of phenomena to which the investigated process belongs and because any particular modelling assumptions as can be justified. If these requirements are met then direct empirical validation may even be dispensable. We conjecture that this is not the case in the absence of comprehensive theoretical background knowledge

Wissenschaft ohne Wahrheit und Erkenntnis. Das Problem epistemischer Verantwortung am Beispiel empirieferner Computersimulationen

Epistemic Responsibility means that scientists are responsible for their research being suitable to contribute to our understanding of the world, or at least some part of the world. As will be shown with the example of computer simulations in social sciences, this is unfortunately far from being understood as a matter of course. Rather, there exist whole research traditions in which the bulk of the contributions is quite free from any tangible purpose of enhancing our knowledge about anything. This essay is concerned with the causes of this phenomenon and pleads for taking epistemic responsibility as a scientific virtue serious. Science should be organized in such a way that it is possible and likely that scientists will assume epistemic responsibility for their research tasks

Die Fallstricke einer intentionalistischen Engführung der Geschichtsdeutung

In this commentary I criticise Doris Gerber's intentionalistic reading of history. While an intentionalistic philosophy of history has some plausibility, a *purely* intentionalistic view is often irreconcilable with the most elementary common sense. For example, that history ought to be considered exclusively as the history of human action and not of things that simply happen to humans as well - like the outbreak of the volcano Vesuv in the year 79 which lead to the destructions of Pompeii. Or that historical value judgments should always be judgments about the reasons for human action, which raises the questions if and how the unintended consequences of human action are to be judged

\u3ci\u3eNebraska Bird Review\u3c/i\u3e (September 1989) 57(3), WHOLE ISSUE

Changes in the A.O.U. Check-list ... 58 1989 (Sixty-fourth) Spring Occurrence Report ... 59 Cassin\u27s Sparrow in Dundy and Chase Counties, Nebraska ... 67 1986: A Nebraska Big Year ... 71 Notes [Scissor-tailed Flycatcher Nest in Cass County, National Wildlife Federation Eagle Survey, and Whooping Crane Report] ... 81 Book Reviews ... 8

What’s Wrong with Social Simulations?

This paper tries to answer the question why the epistemic value of so many social simulations is questionable. I consider the epistemic value of a social simulation as questionable if it contributes neither directly nor indirectly to the understanding of empirical reality. To examine this question, two classical social simulations are analyzed with respect to their possible epistemic justification: Schelling’s neighborhood segregation model and Axelrod’s reiterated Prisoner’s Dilemma simulations of the evolution of cooperation. It is argued that Schelling’s simulation is useful because it can be related to empirical reality, while Axelrod’s simulations and those of his followers cannot and thus that their scientific value remains doubtful. I relate this findingto the background beliefs of modelers about the superiority of the modeling method as expressed in Joshua Epstein’s keynote address “Why model?”

Tools for Evaluating the Consequences of Prior Knowledge, but no Experiments. On the Role of Computer Simulations in Science

There is an ongoing debate on whether or to what degree computer simulations can be likened to experiments. Many philosophers are sceptical whether a strict separation between the two categories is possible and deny that the materiality of experiments makes a difference (Morrison 2009, Parker 2009, Winsberg 2010). Some also like to describe computer simulations as a “third way” between experimental and theoretical research (Rohrlich 1990, Axelrod 2003, Kueppers/Lenhard 2005). In this article I defend the view that computer simulations are not experiments but that they are tools for evaluating the consequences of theories and theoretical assumptions. In order to do so the (alleged) similarities and differences between simulations and experiments are examined. It is found that three fundamental differences between simulations and experiments remain: 1) Only experiments can generate new empirical data. 2) Only Experiments can operate directly on the target system. 3) Experiments alone can be employed for testing fundamental hypotheses. As a consequence, experiments enjoy a distinct epistemic role in science that cannot completely be superseded by computer simulations. This finding in connection with a discussion of border cases such as hybrid methods that combine measurement with simulation shows that computer simulations can clearly be distinguished from empirical methods. It is important to understand that computer simulations are not experiments, because otherwise there is a danger of systematically underestimating the need for empirical validation of simulations

When can a Computer Simulation act as Substitute for an Experiment? A Case-Study from Chemisty

In this article we investigate with a case study from chemistry under what conditions a simulation can serve as a surrogate for an experiment. We set out with a brief discussion of the similarities and differences between simulations and experiments. There are three fundamental differences: 1) Ability (of experiments) to gather new empirical data. 2) Ability to operate directly on the target system. 3) Ability to empirically test fundamental hypotheses. Given that there are such fundamental differences it becomes an important question if and under what conditions simulations can still act as surrogate for experiments. We investigate this question by analysing a simulation of H2 -formation in outer space. We find that in this case the simulation can act as a surrogate for an experiment, because there exists comprehensive theoretical background knowledge about the range of phenomena to which the investigated process belongs and because any particular modelling assumptions as, for example, on the validity of approximations, can be justified. If these requirements are met then direct empirical validation of a “virtual experiment” may even be dispensable. We conjecture that in the absence of comprehensive theoretical background knowledge direct empirical validation of “virtual experiments” remains unavoidable

Moral Judgments of Foreign Cultures and Bygone Epochs. A Two-Tier Approach

In this paper the ethical problem is discussed how moral judgments of foreign cultures and bygone epochs can be justified. After ruling out the extremes of moral absolutism (judging without any reservations by the standards of one's own culture and epoch) and moral relativism (judging only by the respective standards of the time and culture in question) the following solution to the dilemma is sought: A distinction has to be made between judging the norms and institutions in power at a certain place and time and judging people acting within the social institutions of their time and culture. While the former may be judged rigorously, only taking into account the objective possibilities for having other institutions at a certain development stage, the latter should be judged against the background of the common sense morals of the respective time and culture

How Models Fail A Critical Look at the History of Computer Simulations of the Evolution of Cooperation

Abstract Simulation models of the Reiterated Prisoner's Dilemma have been popular for studying the evolution of cooperation since more than 30 years now. However, there have been practically no successful instances of empirical application of any of these models. At the same time this lack of empirical testing and confirmation has almost entirely been ignored by the modelers community. In this paper, I examine some of the typical narratives and standard arguments with which these models are justified by their authors despite the lack of empirical validation. I find that most of the narratives and arguments are not at all compelling. None the less they seem to serve an important function in keeping the simulation business running despite its empirical shortcomings