Co-funded conferences:

•    Conference on Cultural Evolution held in Toulouse (full programme found here: https://ingelaalger.weebly.com/uploads/9/8/9/8/9898358/teb2019.pdf)


Publications:

•    Research Theme 1: Strategic Interactions

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    Preparation and submission of manuscript about an experimental study (Estimating social preferences and Kantian morality in strategic interactions. With Jörgen W. Weibull and 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 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    Preparation and submission of manuscript (Monogamy: Exception or rule?)
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 decreasing in the number of wives under certain conditions and increasing in others. The model thus sheds light on the variation in polygyny rates across space and time in human societies.