We concur with Stibbard-Hawkes' call for caution when using past material culture as an evolutionary or cognitive yardstick, though in our view the paper does not pose a significant challenge to prevailing views and approaches to (what is somewhat controversially referred to as) “behavioural/cognitive modernity”. Whether or not a given population can be decisively said to have crossed this threshold, cognitive modernity did evolve, and much research aims merely to piece together how it came about. We agree with Stibbard-Hawkes that it is not the universal expression of symbolic culture that defines humans but our propensity to reinvent it, and that cognitive propensity still calls for an evolutionary explanation – with or without a reliable archaeological signature.

Current research on “behavioural modernity” has moved on from the kind of simple inferences once made from material chronologies that Stibbard-Hawkes challenges (Meneganzin & Currie, Reference Meneganzin and Currie2022). In the time since these concerns with archaeological inference were first raised by McBrearty and Brooks (Reference Mcbrearty and Brooks2000), explanations of behavioural modernity have broadened from innate neurocognitive adaptations to encompass demographic, ecological, and cultural evolutionary factors, making current efforts subtler and more multi-pronged than their characterization in the target paper. Much research now focuses on identifying adaptive packages of features typifying contemporary human populations (Hill, Barton, & Hurtado, Reference Hill, Barton and Hurtado2009; Migliano & Vinicius, Reference Migliano and Vinicius2022), including neural, social, and ecological mechanisms (Derex & Boyd, Reference Derex and Boyd2015; Migliano et al., Reference Migliano, Battiston, Viguier, Page, Dyble, Schlaepfer and Vinicius2020; Singh et al., Reference Singh, Acerbi, Caldwell, Danchin, Isabel, Molleman and Derex2021), as well as factors pertaining to life history, cooperation, and social and individual learning strategies (Herrmann, Call, Hernàndez-Lloreda, Hare, & Tomasello, Reference Herrmann, Call, Hernàndez-Lloreda, Hare and Tomasello2007; Muthukrishna, Doebeli, Chudek, & Henrich, Reference Muthukrishna, Doebeli, Chudek and Henrich2018; Osiurak, Claidière, & Federico, Reference Osiurak, Claidière and Federico2023; Street, Navarrete, Reader, & Laland, Reference Street, Navarrete, Reader and Laland2017). This research aims for converging evidence from multiple disciplines. To this end, the mechanisms and adaptive context of behavioural modernity in contemporary foragers may provide a more useful test of contemporary theory than material assemblages. For example, one such line of interdisciplinary research develops theories synthesizing data from archaeology, anthropology, neuroscience, and genetics (Chrusch & Gabora, Reference Chrusch, Gabora, Bello, Guarini, McShane and Scassellati2014), and tests these theories using mathematical models (e.g., Gabora & Kitto, Reference Gabora, Kitto and Swan2013; Gabora & Steel, Reference Gabora and Steel2017, Reference Gabora and Steel2020a, Reference Gabora and Steel2020b), and agent-based models (e.g., Gabora & Smith, Reference Gabora and Smith2018). This line of research points to a two-stage model, wherein (1) increased brain size enabled finer-grained mental representations and streams of representational redescription, and subsequently, (2) onset of contextual focus: The capacity to shift between different modes of thought enabled integration of mental contents across contexts and domains (Gabora & Smith, Reference Gabora, Smith, Henley, Kardas and Rossano2019). By endowing neural network-based artificial agents with representational redescription and contextual focus, and observing the hypothesized increases in the fitness and diversity of cultural outputs in different population structures, we gain a richer picture of how archaeological findings may align with cognitive transitions (Gabora & DiPaola, Reference Gabora and DiPaola2012). Thus, current behavioural/cognitive modernity research goes well beyond simple inferences from material chronologies. We add that, at this point, it remains an open question whether there is any universally applicable distinction to be made between archaic and modern.

A related issue is that the problems with material chronologies highlighted in this target paper makes validating the predictions of demographic and cultural evolutionary models as challenging as cognitive evolutionary models, as many of these posit similar phase transitions in evolving cultural and semiotic complexity in the archaeological record (Henrich, Reference Henrich2004). For example, theories of behavioural/cognitive modernity that emphasize changes in between-group migration rates and population densities predict changes in the retention and production of new forms of cultural variation, including symbolic culture (Derex, Perreault, & Boyd, Reference Derex, Perreault and Boyd2018; Grove, Reference Grove2016; Powell, Shennan, & Thomas, Reference Powell, Shennan and Thomas2009). We note that predictor variables related to demography and cultural evolution are not included in the target paper.

Stibbard-Hawkes claims that “contemporary foragers are just as cognitively sophisticated as other contemporary human populations” (sect. 4, para. 1), but the article does not provide sufficient evidence to assess this claim. Indeed, cognitive sophistication is not uniform even amongst contemporary human populations. (For example, individuals from small-scale foraging societies outperform those from industrialized societies at recognizing Müller-Lyer illusions, whereas those without formal education fair worse at inductive logic than those with [Henrich, Heine, & Norenzayan, Reference Henrich, Heine and Norenzayan2010; Nell, Reference Nell1999].) Moreover, even in the absence of significant neurobiological differences (nature), diversity in cognitive sophistication may result from differences in individual learning experiences and culturally transmitted knowledge and beliefs (nurture, see Heyes, Reference Heyes2020), as well as context-dependent differences in creative or analytic thought trajectories culminating in new knowledge and beliefs. This last can be referred to as nous, an ancient Greek concept that refers to intellect, understanding, or reason. Thus, cognitive phenotypes can be said to be the product of nature, nurture, and nous (Gabora & Robertson, Reference Gabora, Robertson, Pérez-Jara and Ongayin press). The idiosyncrasies by which individual instances of nous operate add unique historically dependent variation into the repertoires of populations that are not reducible to nature or nurture; while nature and nurture provide the raw materials, nous forges these raw materials into new ideas. This distinction between “raw materials” and “derived” contents (i.e., nous) arises naturally in an area of network science known as Reflexively Autocatalytic Foodset-generated (RAF) networks, and this is one reason RAF networks have been used to model transitions in cognitive evolution (Gabora & Steel, Reference Gabora and Steel2017, Reference Gabora and Steel2020a, Reference Gabora and Steel2020b). In short, further research would be needed to assess whether contemporary foragers differ from other contemporary human populations with respect to either nurture or nous, and even differences because of nature could have arisen due to the Baldwin effect.

In conclusion, a full understanding of behavioural modernity and its evolution requires an interdisciplinary scientific approach that encompasses nature, nurture, and nous, and this approach is alive and well, despite the challenges of material taphonomy. We close with a final point regarding the target paper. If utilitarian tools are disproportionately likely to contain archaeologically traceable components, as the author claims, that suggests that our ancestors may have been much more creative than what we can surmise from the existing archaeological record.