 Others have explored more specific ideas about how the hallmarks of extended cognition are related to human culture and cultural cognition. Many have examined aspects and implications of our ability to smoothly ‘couple’ our minds with our technology (Clark 2007; Palermos 2014; Carter &amp; Palermos 2016) as well as with our physically and socially constructed environments (Hutchins 2008, 2011; Davidson &amp; Kelly 2020). Others have explored the idea that culture was part of the design problem that selected for minds that are cultural—porous, technologically extendable, deeply socially permeable—in exactly these ways (Tomasello 1999; R. Boyd, Richerson, &amp; Henrich 2011; Dennett 2017; Kelly &amp; Hoburg 2017; Muthukrishna, Doebeli, et al. 2018). Some of this work focuses on material culture and technology (Jeffares 2010; Malafouris 2013; Sterelny 2018), including how artifacts might scaffold or extend specific psychological faculties like memory (Clark 2005; Heersmink forthcoming), mathematical cognition (Menary 2015), or economic reasoning (Clark 1997b). Other work focuses on sociality and social organization (Gallagher 2013; Sterelny 2016, 2021; Carter, Clark, &amp; Palermos 2018b; Gallagher, Mastrogiorgio, &amp; Petracca 2019). Contributors to this strand of research have also explored the ways in which investigations into the nature of culture and extended cognition can dovetail with and help inform investigations into the nature of distributed cognition, collective mental states, and group agency (Hutchins 1995; Tollefsen 2006; Donald 2007; Huebner 2008; Smaldino &amp; Richerson 2013; Jablonka 2017). This line of thought has even inspired hypotheses about the evolution of human brain size, linking increases in collective intelligence, the division of cognitive labor, and the externalization of knowledge with the decrease in the size of individual human brains that appears to have occurred around 3000 years ago (DeSilva et al. 2021).