We question the role given to depiction in Clark and Fischer's account of interaction with social robots. Specifically, we argue that positing a unique cognitive process for handling depiction is evolutionarily implausible and empirically redundant because the phenomena it is intended to explain are not limited to depictive contexts and are better explained by reference to more general cognitive processes.

Drawing from two strands of ecological psychology, we suggest that even if social robots are interactive depictions, people need not mentally represent them as such. Rather, people can engage with the opportunities for action or affordances that social robots offer to them. These affordances are constrained by the larger sociocultural settings within which human–robot interactions occur.

Interactions with social robots are symbolic experiences guided by the pretense that robots depict real people. But they can also be natural experiences that are direct, automatic, and independent of any thoughtful mapping between what is real and depicted. Both experiences are important, both may apply within the same interaction, and they may vary within a person over time.

There are reasons to suspect that meta-cognition about construing social robots as depictions would be more difficult – or absent – than Clark and Fischer discuss. Self-reports about the cognitive processes involved might therefore tend to be incomplete or inaccurate, limiting their usefulness as measures.

The depiction model presents a major advance in our theoretical conceptualization of how humans experience and understand social robots. But the scope of the model is, I suggest, more limited: It pertains to one possible phase in a more comprehensive cognitive-practical dynamics of sense-making (“sociomorphing”) as conceptualized in the OASIS framework. According to the OASIS framework, some basic social actions can be realized by robots, while others may be depicted in the way described by the model.

Clark and Fischer argue that humans treat social artifacts as depictions. In contrast, theories of distributed cognition suggest that there is no clear line separating artifacts from agents, and artifacts can possess agency. The difference is likely a result of cultural framing. As technology and artificial intelligence grow more sophisticated, the distinction between depiction and agency will blur.

Why is it that people simultaneously treat social robots as mere designed artefacts, yet show willingness to interact with them as if they were real agents? Here, we argue that Dennett's distinction between the intentional stance and the design stance can help us to resolve this puzzle, allowing us to further our understanding of social robots as interactive depictions.

The relation between communication partners is crucial for the success of their interaction. This is also true for artificial social agents. However, the more we engage in artificial relationships, the more we are forced to regulate and control them. I refer to this as binding paradox. This deserves attention during technological developments and requires professional supervision during ongoing interactions.

How do we switch between “playing along” and treating robots as technical agents? We propose interaction breakdowns to help solve this “social artifact puzzle”: Breaks cause changes from fluid interaction to explicit reasoning and interaction with the raw artifact. These changes are closely linked to understanding the technical architecture and could be used to design better human–robot interaction (HRI).

In this commentary we would like to question (a) Clark and Fischer's characterization of the “social artifact puzzle” – which we consider less puzzling than the authors, and (b) their account of social robots as depictions involving three physical scenes – which to us seems unnecessarily complex. We contrast the authors' model with a more parsimonious account based on attributions.

We take up issues raised in the commentaries about our proposal that social robots are depictions of social agents. Among these issues are the realism of social agents, experiencing robots, communicating with robots, anthropomorphism, and attributing traits to robots. We end with comments about the future of social robots.

Already as infants humans are more fearful than our closest living primate relatives, the chimpanzees. Yet heightened fearfulness is mostly considered maladaptive, as it is thought to increase the risk of developing anxiety and depression. How can this human fear paradox be explained? The fearful ape hypothesis presented herein stipulates that, in the context of cooperative caregiving and provisioning unique to human great ape group life, heightened fearfulness was adaptive. This is because from early in ontogeny fearfulness expressed and perceived enhanced care-based responding and provisioning from, while concurrently increasing cooperation with, mothers and others. This explanation is based on a synthesis of existing research with human infants and children, demonstrating a link between fearfulness, greater sensitivity to and accuracy in detecting fear in others, and enhanced levels of cooperative behaviors. These insights critically advance current evolutionary theories of human cooperation by adding an early-developing affective component to the human cooperative makeup. Moreover, the current proposal has important cultural, societal, and health implications, as it challenges the predominant view in Western, educated, industrialized, rich, and democratic (WEIRD) societies that commonly construe fearfulness as a maladaptive trait, potentially ignoring its evolutionary adaptive functions.

The “fearful ape hypothesis” is interesting but is currently underspecified. We need more research on whether it is specific to fear, specific to humans (or even cooperative breeders in general), what is included in “fear,” and whether these patterns would indeed evolve despite arms races to extract help from audiences. Specifying these will result in a more testable hypothesis.

A rational economic analysis complements Grossmann's fearful ape hypothesis. Two examples of mixed-motive games with strong inter-dependence (i.e., weak chirping nestling, boxed pigs) demonstrate that signaling weakness is a dominant strategy. Weakness elicits cooperative, caring response, comprising the equilibrium of the game. In extensive form, a reliable reputation of weakness elicits caring as a sequential equilibrium.

Our commentary focuses on the interaction between Grossmann's fearful ape hypothesis (FAH) and the human self-domestication hypothesis (HSDH), also taking into account language acquisition and evolution. Although there is considerable overlap between the two hypotheses, there are also some discrepancies, and our goal is to consider the extent to which HSDH can explain the phenomena identified by FAH without invoking fearfulness as directly adaptive.

Although we find many merits to Grossmann's fearful ape hypothesis, unlike Grossmann, we see heightened fearfulness as an ontogenetic adaptation, signaling helplessness and fostering caregiving during infancy, which subsequently became exapted to promote cooperation. We also argue that, rather than being the “breeding ground” for enhanced infant fearfulness, cooperative care is more likely the evolved product of enhanced fearfulness.

Grossmann's intriguing proposal can benefit from a more thorough integration of the primate literature, particularly on neophobia. Moreover, it directly leads to strong predictions in callitrichids, the only other cooperatively breeding primates beyond humans, which may indeed be met: Being more likely to signal distress than independently breeding monkeys, and responding to such signals with approach and affiliation.

We agree with Grossmann that fear often builds cooperative relationships. Yet he neglects much extant literature. Prior researchers have discussed how fear (and other emotions) build cooperative relationships, have questioned whether fear per se evolved to serve this purpose, and have emphasized that human cooperation takes many forms. Grossmann's theory would benefit from a wider consideration of this work.

We present two challenges to the fearful ape hypothesis: (1) biobehavioral synchrony precedes and moderates the effects of fear on cooperative care, and (2) cooperative care emerges in a more bidirectional manner than Grossmann acknowledges. We present evidence demonstrating how dyadic differences in co-regulation and individual differences in infants' reactivity shape caregivers' responses to infant affect.

Grossmann posits that heightened fearfulness in humans evolved to facilitate cooperative caregiving. We argue that three of his claims – that children express more fear than other apes, that they are uniquely responsive to fearful expressions, and that expression and perception of fear are linked with prosocial behaviors – are inconsistent with existing literature or require additional supporting evidence.