Trix Cacchione

Gravity and Solidity in Four Great Ape Species (Gorilla gorilla, Pongo pygmaeus, Pan troglodytes, Pan paniscus): Vertical and Horizontal Variations of the Table Task

Three experiments modeled after infant studies were run on four great ape species (Gorilla gorilla, Pongo pygmaeus, Pan troglodytes, Pan paniscus) to investigate their reasoning about solidity and gravity constraints. The aims were: (a) to find out if great apes are subject to gravity biased search or display sensitivity for object solidity, (b) to check for species differences, and (c) to assess if a gravity hypothesis or more parsimonious explanations best account for failures observed. Results indicate that great apes, unlike monkeys, show no reliable gravity bias, that ape species slightly differ in terms of their performance, and that the errors made are best explained by a gravity account.

Are apes essentialists? Scope and limits of psychological essentialism in great apes

Abstract Human reasoning is characterized by psychological essentialism (Gelman in The essential child: origins of essentialism in everyday thought. Oxford University Press, New York, 2003): when reasoning about objects, we distinguish between deep essential properties defining the object’s kind and identity, and merely superficial features that can be changed without altering the object’s identity. To date, it is unclear whether psychological essentialism is based on the acquisition of linguistic means (such as kind terms) and therefore uniquely human, or whether it is a more fundamental cognitive capacity which might be present also in the absence of language. In the present study, we addressed this question by testing whether, and if so, under which circumstances non-human apes also rely on psychological essentialism to identify objects. For this purpose, we adapted classical verbal transformation scenarios used in research on psychological essentialism (Keil in Concepts, kinds, and cognitive development. MIT Press, Cambridge, 1989) and implemented them in two nonverbal tasks: first, a box task, typically used to test object individuation (Experiment 1), and second, an object choice task, typically used to test object discrimination, object preferences and logical inferences (Experiments 2–4). Taken together, the results of the four experiments suggest that under suitable circumstances (when memory and other task demands are minimized), great apes engage in basic forms of essentialist reasoning. Psychological essentialism is thus possible also in the absence of language.

The developmental and evolutionary origins of psychological essentialism lie in sortal object individuation.

Cimpian & Salomon (C&S) present promising steps towards understanding the cognitive underpinnings of adult essentialism. However, their approach is less convincing regarding ontogenetic and evolutionary aspects. In contrast to C&Ss claim, the so-called inherence heuristic, though perhaps vital in adult reasoning, seems an implausible candidate for the developmental and evolutionary foundations of psychological essentialism. A more plausible candidate is kind-based object individuation that already embodies essentialist modes of thinking and that is present in infants and nonhuman primates.

Universal Ontology: Attentive Tracking of Objects and Substances across Languages and over Development.

Previous research has demonstrated that adults are successful at visually tracking rigidly moving items, but experience great difficulties when tracking substance-like “pouring” items. Using a comparative approach, we investigated whether the presence/absence of the grammatical count–mass distinction influences adults and children’s ability to attentively track objects versus substances. More specifically, we aimed to explore whether the higher success at tracking rigid over substance-like items appears universally or whether speakers of classifier languages (like Japanese, not marking the object–substance distinction) are advantaged at tracking substances as compared to speakers of non-classifier languages (like Swiss German, marking the object–substance distinction). Our results supported the idea that language has no effect on low-level cognitive processes such as the attentive visual processing of objects and substances. We concluded arguing that the tendency to prioritize objects is universal and independent of specific characteristics of the language spoken.

Domestic horses (Equus ferus caballus) fail to intuitively reason about object properties like solidity and weight

From early infancy, humans reason about the external world in terms of identifiable, solid, cohesive objects persisting in space and time. This is one of the most fundamental human skills, which may be part of our innate conception of object properties. Although object permanence has been extensively studied across a variety of taxa, little is known about how non-human animals reason about other object properties. In this study, we therefore tested how domestic horses (Equus ferus caballus) intuitively reason about object properties like solidity and height, to locate hidden food. Horses were allowed to look for a food reward behind two opaque screens, only one of which had either the proper height or inclination to hide food rewards. Our results suggest that horses could not intuitively reason about physical object properties, but rather learned to select the screen with the proper height or inclination from the second set of 5 trials.

Children use a dispositional core concept when identifying causality

• Children have sophisticated preschool theories of causality • E.g., dispositional theories: causation is an interaction between agents and patients endowed with intrinsic dispositions1 • Asymmetric role distribution of causeand effect-object2 • Research found that these theories are resistant to change3 • Following White’s (2013)4 study, we chose seven events, rated as low to highly causal, based on the number of prototypical features it contains • More causal features -> higher likelihood of causal rating