Co-funded conferences:

•    Conference on Cultural Evolution held in Toulouse in 2019 (full programme found here: teb2019.pdf

•    Conference on Fertility: Causes and Consequences held online in 2021 (full programme found here: teb2019.pdf

•    Conference on Production and Sharing held in Toulouse in 2022 (full programme found here: teb2022.pdf

•    Conference on Inertia held in Toulouse in 2023 (full programme found here: teb2023.pdf)


Publications:

•    Research Theme 1: Strategic Interactions

o    Publication of article: Evolution and Kantian morality: a correction and addendum.  With Jörgen W. Weibull. Games and Economic Behavior, Vol. 140, 2023, 585-587.
Non-technical abstract: In this note we correct a mistake found in our earlier paper Alger and Weibull (Games and Economic Behavior, 2016) (the mistake consisted in using a definition that assumed equilibrium existence, while not guaranteeing  such existence). As a by-product, we also obtain an extension of a result found in Alger and Weibull (Econometrica, 2013).

o    Publication of article: Evolutionarily stable preferences Philosophical Transactions of the Royal Society B, Vol. 378, 2023, 20210505.
Non-technical abstract: The 50-year old definition of an evolutionarily stable strategy (ESS) provided a key tool for theorists to model ultimate drivers of behavior in social interactions. For decades economists ignored ultimate drivers and used models in which individuals choose strategies based on their preferences—a proximate mechanism for behavior, taken to be fixed and given. This article summarizes some key findings in the literature on evolutionarily stable preferences, which in the past three decades has proposed models that combine the two approaches: individuals inherit their preferences, the preferences determine their strategy choices, which in turn determines evolutionary success. One objective is to highlight complementarities and potential avenues for future collaboration between biologists and economists.

o    Publication of article in Journal of Economic Theory (Evolution of preferences in group-structured populations: genes, guns, and culture. Journal of Economic Theory Vol.185, 2020, 104951. With Jörgen W. Weibull and Laurent Lehmann):
Non-technical summary: Although moral values have been part of human thinking for thousands of years, economists have tended to disregard this. Our model examines the evolutionary foundations of moral values. It leads to two main results. First, when individuals reflect on the consequences of their actions on fitnesses, a combination of self-interest and a particular kind of Kantian moral (non-consequentialistic) concern is shown to be compatible with natural selection.  Second, when individuals reflect on the consequences of their actions on material payoffs, a combination of self-interest, a (non-consequentialistic) Kantian moral concern, and a (consequentialistic) concern about the others' material payoffs is shown to be compatible with natural selection. The (consequentialistic) concern may be either pro-social (altruism) or anti-social (spite). The article builds on our earlier work (see the article published in Evolution in 2015). It combines the “island model”, a classic model used by evolutionary biologists to study the effects of population structure, with game theory and classic models of preference evolution in economics, to examine which preferences cannot be displaced by other strategies once they have become prevalent in a population.

o    Publication of article in Journal of Theoretical Politics (Homo moralis goes to the voting booth: coordination and information aggregation. Journal of Theoretical Politics. With Jean-François Laslier.)
Non-technical summary: In previous work together with Jörgen Weibull, I showed that evolutionary forces should be expected to support the prevalence of a particular form of Kantian concern, which in interactions within large populations can be interpreted as partial universalization: an individual with such concerns evaluates action choices in the light of what his or her material payoff would be if, hypothetically, a share of the others were to use the same action as him/her. In this paper we take this partial universalization as a given, and revisit two classical problems in the theory of voting: the divided majority problem and the strategic revelation of information by majority vote. It is shown that, compared to electorates consisting of purely self-interested voters, such partial universalization helps voters solve coordination problems and improves  their ability to aggregate information in an efficient manner, as conjectured by Condorcet

o    Preparation and submission of manuscript about an experimental study (Estimating social preferences and Kantian morality in strategic interactions. With Boris van Leeuwen)
Non-technical summary: Recent theoretical work suggests that a form of Kantian morality has evolutionary foundations. To investigate the relative importance of Kantian morality and social preferences, such as altruism and inequity aversion, we run laboratory experiments on strategic interaction in social dilemmas. Using a structural model, we estimate social preferences and morality concerns both at the individual level and the aggregate level. We observe considerable heterogeneity in social preferences and Kantian morality. Analysis shows that the subject pool is well described as consisting of two types. One exhibits a combination of inequity aversion and Kantian morality, while the other combines spite and Kantian morality.


•    Research Theme 2: The Human Family

o    Publication of article: The evolution of early hominin food production and sharing With Slimane Dridi, Jonathan Stieglitz, and Michael Wilson. Proceedings of the National Academy of Sciences, Vol. 120 (25), 2023, e2218096120.
Non-technical abstract: Human foragers share plant and animal foods extensively. Influential scenarios for the evolution of hominin food sharing focus on either scavenging, hunting, or cooking. However, evidence of extractive foraging for nutrient-dense plant foods millions of years before the emergence of these activities suggests food sharing potentially emerged earlier. We present a novel conceptual and mathematical model of the evolution of food production and sharing in early hominins across diverse mating systems. Male mate guarding protects females from food theft, permitting females to increase extractive foraging time and efficiency. Increased efficiency motivates females to share food with males when pair bonds exist. Female provisioning of males may have catalyzed the evolution of uniquely hominin traits prior to dietary reliance on meat.


o    Publication of survey article in Oxford Research Encyclopedia (Evolution of the Family: Theory and Implications for Economics. With Donald Cox)
Non-technical summary: Which parent can be expected to be more altruistic toward their child, the mother or father? All else equal, can we expect older generation members to be more solicitous of younger family members or vice versa? Policy interventions often target recipients by demographic status: more money being put in the hands of mothers, say, or transfers of income from young to old via public pensions. Economics makes predictions about pecuniary incentives and behaviour, but tends to be agnostic about how, say, a post-menopausal grandmother might behave, just because she is a post-menopausal grandmother. Evolutionary theory fills this gap by analysing how preferences of family members emerge from the Darwinian exigencies of “survive and reproduce.” Coin of the realm is so-called “inclusive fitness,” reproductive success of oneself plus that of relatives, weighted by closeness of the relationship. Appending basic biological traits onto considerations of inclusive fitness generates predictions about preferences of family members. A post-menopausal grandmother with a daughter just starting a family is predicted to care more about her daughter than the daughter cares about her, for example. Evolutionary theory predicts that mothers tend to be more altruistic toward children than fathers, and that close relatives would be inclined to provide more support to one another than distant relatives. An original case study is provided, which explains the puzzle of diverging marriage rates by education in terms of heterogeneity in preferences for commitment. Economists are justifiably loathe to invoke preferences to explain trends, since preference-based explanations can be concocted to explain just about anything. But the evolutionary approach does not permit just any invocation of preferences. The dictates of “survive and reproduce” sharply circumscribe the kinds of preference-related arguments that are admissible.

o    Publication of article in PNAS (Paternal provisioning results from ecological change. Proceedings of the National Academy of Sciences, 117 (20), 2020, 10746-10754. With Donald Cox, Paul Hooper, Hillard Kaplan, and Jonathan Stieglitz)
Non-technical summary: Paternal provisioning is ubiquitous in human subsistence societies and unique among apes. How could paternal provisioning have emerged from promiscuous or polygynous mating systems that characterize other apes? An anomalous provisioning male would encounter a social dilemma: Since this investment in prospective offspring can be expropriated by other males, this investment is unlikely to increase the provisioner’s fitness. We present an ecological theory of the evolution of human paternal investment. Ecological change favoring reliance on energetically rich, difficult-to-acquire resources increases payoffs to paternal provisioning due to female–male and/or male–male complementarities. Paternal provisioning becomes a viable reproductive strategy when complementarities are strong, even under high paternity uncertainty. This model illuminates additional paths for understanding the evolution of fatherhood.

o    Publication of article in Journal of Economic Behavior and Organization (On the evolution of male competitiveness. Journal of Economic Behavior and Organization Vol. 190, 2021, 228-254)
Non-technical summary: Why are some societies monogamous and others polygynous? Most theories of polygyny invoke male heterogeneity as an explanation. Arguing that such heterogeneity depends on men’s willingness to compete against each other in the first place, I propose an evolutionary game to model the evolution of this trait. Lack of competitiveness (and the associated monogamous unions) is shown to be compatible with evolution if male reproductive success decreases with the number of wives. In a model where the man and his spouse(s) make fertility and child care choices that aim at maximizing reproductive success, I show that, due to men’s involvement in child care and female agency over her fertility, male reproductive success is indeed decreasing in the number of wives under certain conditions, while it is increasing under other condition The model thus sheds light on the variation in polygyny rates across space and time in human societies.