The Preference for Pointing With the Hand Is Not Universal

Empirical challenges from the comparative and developmental literature to the Shared Intentionality Theory - a review of alternative data on recursive mind reading, prosociality, imitation and cumulative culture

Humans have an irresistible inclination to coordinate actions with others, leading to species-unique forms of cooperation. According to the highly influential Shared Intentionality Theory (SITh), human cooperation is made possible by shared intentionality (SI), typically defined as a suite of socio-cognitive and motivational traits for sharing psychological states with others, thereby enabling individuals to engage in joint action in the mutually aware pursuit of shared goals. SITh theorises that SI evolved as late as 400,000 years ago, when our ancestors (in particular, Homo heidelbergensis) turned to a kind of food procurement that obligatorily required joint coordinated action. SI is, thus, hypothesized to be absent in other extant species, including our closest genetic relatives, the nonhuman great apes ("apes"). According to SITh, ape psychology is exclusively driven by individualistic motivations, as opposed to human psychology which is uniquely driven by altruistic motivations. The evolutionary scenario proposed by SITh builds on a series of findings from socio-cognitive research with apes and human children, and on the assumption that abilities expressed early in human development are human universals, unlikely to have been shaped by socio-cultural influences. Drawing on the primatological and developmental literature, we provide a systematic - albeit selective - review of SITh-inconsistent findings concerning psychological and behavioural traits theorised to be constitutive of SI. The findings we review pertain to all three thematic clusters typically addressed in SITh: (i) recursive mind reading; (ii) prosociality; (iii) imitation and cumulative culture. We conclude that such alternative data undermine two core SITh claims: the late evolutionary emergence of SI and the radical divide between ape and human psychology. We also discuss several conceptual and methodological limitations that currently hamper reliable comparative research on SI, in particular those engendered by Western-centric biases in the social sciences, where an overreliance on Western samples has promoted the formulation of Western-centric conceptualisations, operationalisations and methodologies.

Interactionally Embedded Gestalt Principles of Multimodal Human Communication

Natural human interaction requires us to produce and process many different signals, including speech, hand and head gestures, and facial expressions. These communicative signals, which occur in a variety of temporal relations with each other (e.g., parallel or temporally misaligned), must be rapidly processed as a coherent message by the receiver. In this contribution, we introduce the notion of interactionally embedded, affordance-driven gestalt perception as a framework that can explain how this rapid processing of multimodal signals is achieved as efficiently as it is. We discuss empirical evidence showing how basic principles of gestalt perception can explain some aspects of unimodal phenomena such as verbal language processing and visual scene perception but require additional features to explain multimodal human communication. We propose a framework in which high-level gestalt predictions are continuously updated by incoming sensory input, such as unfolding speech and visual signals. We outline the constituent processes that shape high-level gestalt perception and their role in perceiving relevance and prägnanz. Finally, we provide testable predictions that arise from this multimodal interactionally embedded gestalt-perception framework. This review and framework therefore provide a theoretically motivated account of how we may understand the highly complex, multimodal behaviors inherent in natural social interaction.

Caregiver Perceptions of Social Communication and Interaction: Development and Validation of the SCIPS

Social communication and interaction (SC/I) skill quality may be influenced by cultural values, norms, and expectations. Because difficulties in SC/I is a core criterion for identifying autism and is a frequent construct of interest in autism research, a measure designed to capture cross-cultural differences in the perspectives of SC/I skills is warranted. To address this need we developed and validated the Social Communication and Interaction Perceptions Scale (SCIPS), a caregiver report measure for children ages 6-18 years, that measures both frequency and perceived importance of various SC/I skills. Results from 401 diverse caregiver participants showed that for both domains (i.e., Frequency and Importance) the SCIPS has good reliability (α = 0.88-0.95) and two factors that examine basic and advanced aspects of SC/I skills. Findings support the use of the SCIPS as a measure of caregiver perspectives of SC/I skills in clinical and research contexts.

Making Referents Seen and Heard Across Signed and Spoken Languages: Documenting and Interpreting Cross-Modal Differences in the Use of Enactment

Differences in language use and structures between signed and spoken languages have often been attributed to so-called language “modality.” Indeed, this is derived from the conception that spoken languages resort to both the oral-aural channel of speech and the visual-kinesic channel of visible bodily action whereas signed languages only resort to the latter. This paper addresses the use of enactment, a depictive communicative strategy whereby language users imitate referents in signed and spoken languages. Reviewing comparative research on enactment, this paper highlights theoretical and methodological shortcomings in prior works. First, a broader set of causal explanations needs to be taken into account when interpreting differences between signing and speaking communities. A more comprehensive conceptual toolbox ensures that differences are not automatically attributed to modality. In particular, less-studied factors of language diversity, like sociolinguistic and cultural ecologies, and how they interact with other factors should be considered. Second, diversity in enactment across signed and spoken languages is shown to be inadequately and insufficiently documented. It is argued that by comparing enactment across more diverse signing and speaking communities and using large, directly comparable corpora, solid analyses can be carried out, enabling a better understanding of how and why different communities use enactment in similar or different ways.

A socio-ecological perspective on the gestural communication of great ape species, individuals, and social units

Over the last 30 years, most research on non-human primate gestural communication has been produced by psychologists, which has shaped the questions asked and the methods used. These researchers have drawn on concepts from philosophy, linguistics, anthropology, and ethology, but despite these broad influences the field has neglected to situate gestures into the socio-ecological context in which the diverse species, individuals, and social-units exist. In this review, we present current knowledge about great ape gestural communication in terms of repertoires, meanings, and development. We fold this into a conversation about variation in other types of ape social behaviour to identify areas for future research on variation in gestural communication. Given the large variation in socio-ecological factors across species and social-units (and the individuals within these groups), we may expect to find different preferences for specific gesture types; different needs for communicating specific meanings; and different rates of encountering specific contexts. New tools, such as machine-learning based automated movement tracking, may allow us to uncover potential variation in the speed and form of gesture actions or parts of gesture actions. New multi-group multi-generational datasets provide the opportunity to apply analyses, such as Bayesian modelling, which allows us to examine these rich behavioural landscapes. Together, by expanding our questions and our methods, researchers may finally be able to study great ape gestures from the perspective of the apes themselves and explore what this gestural communication system reveals about apes’ thinking and experience of their world.

Cultural differences in social communication and interaction: A gap in autism research

Social communication and interaction deficits are a diagnostic criteria of autism and integral to practitioner and researcher conceptualization. Culture is an influential factor in expectations for, and demonstration of, social communication and interaction skills, but there is limited research published in autism journals on this topic. This paucity of autism research examining cultural factors related to social communication and interaction may contribute to known identification disparities for racial and ethnic populations minoritized by systemic factors and research bias. We call for increased commitment from researchers to recruit racially and ethnically minoritized participants, prioritize investigating cultural expectations and perceptions of social communication and interaction, and evaluate measures related to social communication for cultural and linguistic responsivity. LAY SUMMARY: A diagnosis of autism requires the presence of deficits in social communication and interaction. Examples of these behaviors and skills include holding a back-and-forth conversation, the use of nonverbal communicative behaviors (e.g., gestures), and developing and maintaining social relationships. Culture influences the expectations for, and presentation of, these behaviors. However, research on this topic is lacking. Conducting more research related to culture and social communication could help reduce the disparities in autism identification across racially and ethnically minoritized populations.

A conceptual framework for the study of demonstrative reference

Language allows us to efficiently communicate about the things in the world around us. Seemingly simple words like this and that are a cornerstone of our capability to refer, as they contribute to guiding the attention of our addressee to the specific entity we are talking about. Such demonstratives are acquired early in life, ubiquitous in everyday talk, often closely tied to our gestural communicative abilities, and present in all spoken languages of the world. Based on a review of recent experimental work, here we introduce a new conceptual framework of demonstrative reference. In the context of this framework, we argue that several physical, psychological, and referent-intrinsic factors dynamically interact to influence whether a speaker will use one demonstrative form (e.g., this) or another (e.g., that) in a given setting. However, the relative influence of these factors themselves is argued to be a function of the cultural language setting at hand, the theory-of-mind capacities of the speaker, and the affordances of the specific context in which the speech event takes place. It is demonstrated that the framework has the potential to reconcile findings in the literature that previously seemed irreconcilable. We show that the framework may to a large extent generalize to instances of endophoric reference (e.g., anaphora) and speculate that it may also describe the specific form and kinematics a speaker's pointing gesture takes. Testable predictions and novel research questions derived from the framework are presented and discussed.

Effects of Scale on Multimodal Deixis: Evidence From Quiahije Chatino

As humans interact in the world, they often orient one another's attention to objects through the use of spoken demonstrative expressions and head and/or hand movements to point to the objects. Although indicating behaviors have frequently been studied in lab settings, we know surprisingly little about how demonstratives and pointing are used to coordinate attention in large-scale space and in natural contexts. This study investigates how speakers of Quiahije Chatino, an indigenous language of Mexico, use demonstratives and pointing to give directions to named places in large-scale space across multiple scales (local activity, district, state). The results show that the use and coordination of demonstratives and pointing change as the scale of search space for the target grows. At larger scales, demonstratives and pointing are more likely to occur together, and the two signals appear to manage different aspects of the search for the target: demonstratives orient attention primarily to the gesturing body, while pointing provides cues for narrowing the search space. These findings underscore the distinct contributions of speech and gesture to the linguistic composite, while illustrating the dynamic nature of their interplay.

Abstracts in Spanish and Quiahije Chatino are provided as appendices.

Se incluyen como apéndices resúmenes en español y en el chatino de San Juan Quiahije. Son^G ktyi^C re^C in^H, ngyaq^C ska^E ktyi^C no^E nda^H son^B na^F nga^J no^I ngyaq^C lo^E ktyi^C re^C, ngyaq^C ran^F chaq^E xlya^K qo^E chaq^F jnya^J no^A ndywiq^A renq^A Kchin^A Kyqya^C.

The Referential Problem Space revisited: An ecological hypothesis of the evolutionary and developmental origins of pointing

Pointing by great apes poses a significant challenge to contemporary theories about the evolutionary and developmental foundations of cognitive development, because pointing has long been viewed by theoreticians as an evolved, human-unique developmental stepping-stone to linguistic reference. Although reports of pointing by great apes have existed in the scientific literature for over a century, only in recent decades has it become clear that ape pointing is definitely an intentionally communicative signal, by the same criteria we adjudge human pointing to be intentionally communicative. Theoretical responses to this changed empirical landscape have generally taken the approach of asserting, without any direct evidence (indeed, in the absence of any possibility of direct evidence), that pointing by humans is psychologically distinct from and more cognitively complex than the pointing of apes. It is commonplace in the contemporary literature to appeal to imaginary, species-unique causal factors to account for human pointing, rendering a large body of contemporary theoretical work untestable with scientific methods: scientific arguments require the public availability of core theoretical entities. In this paper, I will analyze the circumstances of pointing by apes and humans and develop an alternative theoretical model of pointing that does not rely upon non-physical constructs. According to the view espoused, here, pointing develops as a solution to a particular kind of developmental problem, characterized by (a) a developing capacity for tool use, (b) barriers to direct action, and (c) a history of caregiver responsiveness. Pointing by both apes and humans is explicable without invoking imaginary, mental causes. This article is categorized under: Cognitive Biology > Evolutionary Roots of Cognition Cognitive Biology > Cognitive Development Psychology > Comparative Psychology.

Ontogeny vs. phylogeny in primate/canid comparisons: A meta-analysis of the object choice task

The Object Choice Task (OCT) is a widely used paradigm with which researchers measure the ability of a subject to comprehend deictic (directional) cues, such as pointing gestures and eye gaze. There is a widespread belief that nonhuman primates evince only a weak capacity to use deictic cues; in contrast, domestic dogs (Canis lupus familiaris) tend to demonstrate high success rates. This pattern of canid superiority has been taken to support the Domestication Hypothesis, which posits enhancing effects of artificial selection on the sociocognitive abilities of dogs and humans. Here we review nearly two decades of published findings, using variants of the OCT. We find systematic confounds with species classification in task-relevant preparation of the subjects, in the imposition of a barrier between reward and subject, and in the specific deictic cues used to indicate the location of hidden objects. Thus, the widespread belief that dogs outperform primates on OCTs is undermined by the systematic procedural differences in the assessments of these skills, differences that are confounded with taxonomic classification.

The what and the how: Information-seeking pointing gestures facilitate learning labels and functions

Infants' pointing gestures are clear and salient markers of their interest. As a result, they afford infants with a targeted and precise way of eliciting information from others. The current study investigated whether, similar to older children's question asking, infants' pointing gestures are produced to obtain information. Specifically, in a single experimental study, we examined whether 18-month-olds (N = 36) point to request specific types of information and how this translates into learning across domains. We elicited pointing from infants in a context that would naturally lend itself to information seeking (i.e., out-of-reach novel objects). In response to infants' points, an experimenter provided a label, a function, or no information for each pointed-to object. We assessed infants' persistence after receiving different types of information and their subsequent ability to form label-object or function-object associations. When infants pointed and received no information or functions, they persisted significantly more often than when they pointed and received labels, suggesting that they were most satisfied with receiving labels for objects compared with functions or no information. Infants successfully mapped both labels and functions onto objects. When infants expressed their interest in a novel object in a manner other than pointing, such as reaching, they (a) were equally satisfied with receiving object labels, functions, or no information and (b) did not successfully learn either labels or functions. Together, these findings demonstrate that infants' pointing gestures are specific requests for labels that facilitate the acquisition of various types of information. In doing so, this work connects the research on information seeking during infancy to the established literature on question asking during childhood.