The rapid appearance (over evolutionary time) of the cognitive skills and complex inventions of modern humans has been attributed to “cumulative cultural evolution” (CCE), the accumulation of knowledge and skills over generations. To date, researchers have only been able to speculate about the reasons for the apparent absence of this phenomenon in nonhumans, and it has not been possible to test hypotheses regarding the mechanisms underlying it. Here, we show that it is possible to demonstrate CCE under laboratory conditions by simulating generational succession through the repeated removal and replacement of human participants within experimental groups. We created “microsocieties” in which participants were instructed to complete simple tasks using everyday materials. In one of our procedures, participants were instructed to build a paper aeroplane which flew as far as possible, and in the other, they were instructed to construct a tower of spaghetti which was as tall as possible. We show that, in both cases, information accumulates within the groups such that later generations produce designs which are more successful than earlier ones. These methods offer researchers a window to understanding CCE, allowing for experimental manipulation and hypothesis testing.
The rapid appearance (over evolutionary time) of the cognitive skills and complex inventions of modern humans has been attributed to “cumulative cultural evolution” (CCE) (Boyd and Richerson, 1996, Richerson and Boyd, 2005 and Tomasello, 1999). The term CCE is used to describe the way that knowledge accumulates in human populations over time, such that each generation makes use of behaviours and artefacts invented by previous generations, which they would be unlikely to have been able to invent by themselves ( Boyd and Richerson, 1996, Richerson and Boyd, 2005 and Tomasello, 1999). It has been argued that, although social learning is relatively common in the animal kingdom, CCE is extremely rare, possibly restricted to humans ( Boyd and Richerson, 1996, Galef, 1992 and Tomasello, 1999). It has also been suggested that CCE may even be dependent on learning mechanisms which are unique to humans and is consequently not possible in nonhumans ( Tomasello, 1999), although this remains contentious (e.g., see Whiten, Horner, & Marshall-Pescini, 2003). Understanding CCE may therefore represent an important element in understanding human nature, particularly as it has allowed humans to develop powerful technologies, assemble complex societies, use symbolic forms of communication, and exploit an unusually wide range of habitats ( Boyd & Richerson, 1996). However, to date, research on CCE has been restricted to historical approaches, such as those which classify and sequence human artefacts ( Basalla, 1989 and O'Brien et al., 2001), and comparative approaches, which draw comparisons between human behaviour and that of other animals, such as chimpanzees ( Boesch, 2003, Tomasello et al., 1993, Tomasello et al., 1993 and Whiten et al., 2003). Therefore, researchers have only been able to speculate about the reasons for its apparent absence (or at least its relative rarity, e.g., see Boesch, 2003) in other species and the abilities upon which it depends in humans.
