Interview with Karl Sigmund
“Don’t expect new paradigms from old brains!”
Our guest of honor today is Karl Sigmund, a high-caliber polymath who left his fingerprints in evolutionary game theory and beyond. He is among the few who can seamlessly weave logic, mathematics, biology, economics, history, and philosophy, into an impressive piece of art. Game theory lies at the crossroads of several fields of knowledge, and Sigmund was no doubt able to master all.
In his writings, you will find some recurrent themes, but you will always find something new. The breadth of knowledge, the elegant style, the deep insights, and the down-to-earth applications to real-world problems, coalesce in a delicate balance. While his style is friendly, you need a good background to appreciate his contributions. His writings should be high on the reading list of graduate students of economics and science in general.
Sigmund was born in a small town in lower Austria, Gars am Kamp, on 26 July 1945. He went to a French secondary school in Vienna. In 1968 he obtained his Ph.D. at the Institute of Mathematics at the University of Vienna under the supervision of Leopold Schmetterer.
In 1973 he was appointed Professor at the Institute of Mathematical Statistics in Göttingen where he spent one year before moving back to the University of Vienna where he became a full professor at the Institute for Mathematics. In the same year, 1974, he married the historian and author Anna Maria; they have one son, Willi.
He was the head of the Institute of Mathematics from 1983 to 1985. He was vice-president (1995 to 1997) and then president (1997 to 2001) of the Austrian Mathematical Society. He was a member of the Austrian and German Academies of Science (1999 to 2003). From 2003 to 2005 he was vice-president of the Austrian Science Fund (FWF).
In 2010 Sigmund was elected a member of the European Academy of Science and, in the same year, awarded an honorary doctorate by the University of Helsinki. In 2011, he was awarded the Blaise Pascal Medal for Mathematics by the European Academy of Science. In 2012 he received the Isaacs Award, a prize offered by the International Society of Dynamic Games to recognize the “outstanding contribution to the theory and applications of dynamic games.” In 2013, he received the “UNIVIE Teaching Award 2013” by the University of Vienna for outstanding teaching achievements. He received the Science Book of the Year Prize from the Austrian Federal Ministry of Science, Research and Economy in 2016 for his book Exact Thinking in Demented Times: The Vienna Circle and the Epic Quest for the Foundations of Science.
Sigmund published widely in leading journals, including Nature, Science, and Journal of Theoretical Biology, among others. His acclaimed books are addressed to the educated public, and they offer an invaluable window into the advanced interdisciplinary work he and his collaborators contributed. Most notably:
- Games of Life: Explorations in Ecology, Evolution and Behavior (1994) Oxford University Press, updated 2017.
- The Calculus of Selfishness (2010) Princeton University Press.
- Exact Thinking in Demented Times: The Vienna Circle and the Epic Quest for the Foundations of Science (2017) with a Foreword by Douglas Hofstadter, Basic Books.
- The Waltz of Reason: The Entanglement of Mathematics and Philosophy (2023) Basic Books.
A complete list of his publications can be found on his website.
GL: Let us start with Gödel. It seems you became interested in Gödel’s works quite early in your career. What was the motivation behind that? Did you have the chance to meet him?
KS: My interest in Gödel dates back to my first weeks at the University of Vienna. Together with some fellow students, I became fascinated by the foundations of mathematics. Two of us (Werner Schimanovich and the artist Peter Weibel) even produced a TV documentary on him, at a very early stage. Unfortunately, I never met Kurt Gödel in person. I met a few — such as my mathematics professor Edmund Hlawka and the computer pioneer Franz Alt — who knew him from way back in the ‘thirties in Vienna.
GL: Is incompleteness, or undecidability in general, relevant to social sciences and game theory in particular? For example, it might be argued that, in many cases, undecidability implies that there might not exist perfectly rational, Pareto optimal solutions to critical economic problems. For this reason, social norms and institutions naturally emerge to fill in the void.
How might undecidability influence our understanding of rational decision-making in economic and social contexts?
KS: The incompleteness theorems are tremendously Important, but they apply to formal systems and arithmetic. This is their biotope. I am skeptical about ascribing to Gödel everything that has to do with limits of rationality etc. In particular, human communities are shaped by evolutionary forces, and social norms existed long before anyone thought of Pareto-optimality.
By the way, Kurt Gödel was closely acquainted with Oskar Morgenstern and John von Neumann but seems not to have been interested in their brainchild, game theory. His philosophical notebooks, which are now being transcribed and published at a fast pace, reveal that he was very interested in problems of ethics, but these concern almost exclusively individual ethics (how to optimize one-self, so to speak) but hardly group ethics (fairness, social contract, etc.).
GL: But Gödel was interested in economics, wasn’t he?
KS: Let us say that he followed with interest the talks of Abraham Wald on economic equilibrium, and asked some very pertinent questions concerning Walras-Cassel equations. But to my knowledge, this had no ethical aspect.
GL: In November 2008, shortly after the onset of the Global Financial Crisis, the Queen of England asked the economists at the London School of Economics: “Why did no one see it coming?” The economists responded by saying, in essence, that market players were individually rational, but collectively they were not.
This seems like a classical Prisoner’s Dilemma scenario. If this is the case, why are economists still occupied with individual rationality at the expense of collective rationality?
KS: There seem indeed still to exist economists who believe in rationality as a main force behind human behavior. The lessons of psychology and behavioral economics are clearly lost on them. I should add that many of the greatest thinkers on the economy, such as Adam Smith or John Maynard Keynes, were well aware of the role of “human nature” or “animal spirits” in shaping our behavior. It is so convenient to forget that.
As to “Why did no one see it coming?”, the great Isaac Newton asked himself the same question after having lost much of his fortune In the South Sea Bubble. He ruefully concluded, “I can calculate the motions of heavenly bodies but not the madness of people.” This madness is still difficult to handle; a rational actor seems so much easier to predict; so let’s develop rational decision theory, and forget the ugly face of real life, and everything becomes much easier, right?
GL: Can’t we add “undecidability” or “limits to reason” to the lessons of psychology and behavioral economics to strengthen the case for an alternative paradigm for social sciences?
KS: This depends on our definition of “undecidability” and “limits to reason”. Personally, I would prefer to use the terms “unpredictability” and “limits to computation”. Chaos theory is (to my mind) more relevant than metamathematics towards a better understanding of social sciences.
GL. Symmetry plays a major role in modern science. It seems to be woven into the fabric of nature. Do you think it could be of value for social sciences, especially economics? Could symmetry explain the observed universal preference for fairness in social interactions?
KS: Symmetry can explain a lot. However, I am not sure how to explain symmetry.
GL: But why symmetry is ignored in economics and social sciences?
KS: I hesitate to concur with you. For instance, in John Nash’s theory of sharing, symmetry plays surely an essential role.
GL: Economics is traditionally defined as the science of scarcity. In the light of Social Dilemmas, it seems there are two kinds of scarcity:
- Natural scarcity, which arises from the finiteness of physical resources.
- Social scarcity, which arises from resource-related Social Dilemmas, e.g., the Tragedy of the Commons.
How could game theory help us reconceptualize the notion of scarcity, taking into account these dimensions?
KS: Let us never forget that we are experts in game theory since thousands of generations of living in groups, in the same sense as we are experts in mechanics: we can throw stones, or forge social bonds, without being aware of the theoretical aspects behind It. Game theory can help us in gaining a better understanding of scarcity, but not necessarily in handling it.
GL: Can game theory (as a theory) help to redefine the main problem of economics, namely scarcity?
KS: I agree with you: game theory is indeed a good tool to conceptualize the existential problem of scarcity.
GL: Some writers argue that there is no such thing as a Prisoner’s Dilemma game in nature. It is purely a social scenario. What do you think?
KS: The Prisoner’s Dilemma is (obviously) a social phenomenon, but deeply embedded in biology. There are even bacteria who play it. On the other hand, the “reciprocity solution” seems pretty much restricted to human communities.
GL: In your 1993 book, Games of Life, you explore how robots may acquire some features of living organisms. With the recent surge in AI applications, how do you see the impact of AI on the dynamics of social life?
KS: Yes, we seem really to be caught in an avalanche.
GL. Have any of your views discussed in your books changed over the past 30 years?
KS: I had no idea of the impact of AI. My views have changed too little, the world has changed too much.
GL: Your book, Exact Thinking in Demented Times: The Vienna Circle and the Epic Quest for the Foundations of Science, attracted a lot of attention given its unique documentation of the historical and intellectual developments in Vienna between the two World Wars. Are there plans to produce a movie based on the book?
KS: I have produced two TV documentaries (one on Albert Einstein in Vienna, and one on Otto Neurath) and it was an awful stress. So, I’ll never do it again. But I know of some people who are exploring the idea.
GL. Do you think we live now in “demented times”?
KS: Of course!
GL: Demented times usually give birth to new paradigms. What are the new paradigms that you think will emerge from the current turmoil?
KS: Don’t expect new paradigms from old brains!
GL: In Exact Thinking, you present the views of Moritz Schlick on the “meaning of life.” It centers around being “open to play.” This seems an interesting view in the context of game theory. Is it possible to model the “preference to play” as envisioned by Schlick?
KS: I love Schlick’s emphasis on “openness to play”. (Whether it gives meaning to life is another question — in any case, it adds some interest to life). Many animals use play to explore their surrounding (and to train their own faculties), so it would be interesting to model this as an evolved trait — but I know no references for this.
GL: What are your 3 most important recommendations to young researchers in economics and science in general?
KS: (1) Forget the mainstream; (2) trust your instincts; (3) don’t listen to recommendations by old scientists 😉.
GL: Thank you for being our guest and offering your enlightening answers.
KS: You’re welcome!
