1) For @Noahpinion who wants to know "What the heck is group selection?" To motivate you, it is the future foundation of economics. Here it is in the space of a few tweets. @EvonomicsMag @econnaturalist @EricBeinhocker @yaneerbaryam @BretWeinstein @hangingnoodles @NickHanauer...
2) At first, Darwin thought his theory could explain all examples of design attributed to a creator. Gradually he realized that his theory could not explain prosocial adaptations--anything oriented toward the welfare of others or one's group as a whole...
3) Why? Because prosocial traits are less fit than more self-oriented traits within the same social group. Natural selection is based on relative fitness, not absolute fitness, a departure from standard economic thinking, as pointed out by your colleague @econnaturalist ...
4) ...The selective disadvantage of prosocial traits within groups is a basic matter of tradeoffs. Helping others or one's group as a whole requires time, energy, & risk on the part of the individual. Maybe some exceptions, but no doubt about the rule....
5) ...If a prosocial trait is selectively disadvantageous within each and every group of a multi-group population, how can it evolve? Only by a selective advantage at a larger scale. Groups with more prosocial members outcompete groups with fewer prosocial members...
6) ...Thus, you can say that group selection is an addendum that Darwin needed to add to his theory of natural selection to explain prosocial adaptations. It's that simple and general...
7) ...That's why E.O. Wilson and I concluded our 2007 article "Rethinking the Theoretical Foundation of Sociobiology" this way: "Selfishness beats altruism within groups. Altruistic groups beat selfish groups. Everything else is commentary. " journals.uchicago.edu/doi/abs/10.108…...
8) There is much more unity about how to define groups than you might think. Why? For nonsocial traits, the fitness of an individual is based entirely on its own properties. But for social traits, you can't calculate the fitness of an individual without known the properties...
9) ...of the others with whom it interacts. The set of socially interacting individuals determining each other's fitness is the group. All models of social evolution must define groups in this way just to calculate the fitness of individuals...
10)...This means that the basic logic of within- and between-group selection is embedded in all theories of social evolution, even those that were developed as alternatives to group selection. This is known as equivalence...
11) ...Most critics of group selection are like someone who faces away from an object, bends over, looks between their legs, and claims to see a new object. For example, the concept of vehicles in selfish gene theory gives back exactly what it took away in its denial of GS...
12)...For more, read your own colleagues applying these ideas to economics, such as @econnaturalist, @EricBeinhocker Sam Bowles, @hgintis, @JoHenrich @Peter_Turchin--even Friedrich Hayek as an early pioneer, although his account requires extensive updating....
13) As @econnaturalist puts it, in the future Darwin, not Adam Smith, will be regarded as the father of economics. Here is a @tvolmag interview with him to get you started.Many other articles available on @tvolmag and @EvonomicsMag. evolution-institute.org/charles-darwin…...
14) Notice that all this can easily be stated in words without requiring formal mathematical models. Of course formal models are useful, in conjunction with lab experiments and field studies of evolution in multi-group populations, which exist in abundance. Twitter lesson over.
