see
https://www.researchgate.net/profile/Peter_Kramer/publication/272478550_Humans_as_Superorganisms_How_Microbes_Viruses_Imprinted_Genes_and_Other_Selfish_Entities_Shape_Our_Behavior/links/59e9bc31aca272bc42b72080/Humans-as-Superorganisms-How-Microbes-Viruses-Imprinted-Genes-and-Other-Selfish-Entities-Shape-Our-Behavior.pdf