Developmental Origins of Biological Explanations: The case of infants’ internal property bias

Abstract

People's explanations about the biological world are heavily biased toward internal, non-obvious properties. Adults and children as young as 5 years of age find internal properties more causally central than external features for explaining general biological processes and category membership. In this paper, we describe how this 'internal property bias' may be grounded in two different developmental precursors observed in studies with infants: (1) an early understanding of biological agency that is apparent in infants' reasoning about animals, and (2) the acquisition of kind-based representations that distinguish between essential and accidental properties, spanning from animals to artifacts. We argue that these precursors may support the progressive construction of the notion of biological kinds and explanations during childhood. Shortly after their first year of life, infants seem to represent the internal properties of animates as more central and identity-determining that external properties. Over time, this skeletal notion of biological kinds is integrated into diverse explanations about kind membership and biological processes, with an increasingly better understanding of the causal role of internal properties.

The Privileged Status of Knowing Mechanistic Information: An Early Epistemic Bias

“…For example, 14‐month‐olds assume that a specific internal part, but not an external “hat” of the same size and shape, will predict an animal's behavior (Newman, Herrmann, Wynn, & Keil, ). This internal parts bias has been interpreted as central to organizing beliefs about kind identity (Taborda‐Osorio & Cheries, ). However, in infancy it may be devoid of any preferences for mechanism per se (ibid).…”

Animacy cues facilitate 10-month-olds' categorization of novel objects with similar insides

“…This developmental continuity from infancy to preschool, however, does not imply that infants share the same causal expectations about insides features that preschoolers do. Instead, we favor the account recently put forth by Taborda-Osorio and Cheries [ 19 ] which proposes that that there are developmental precursors to later biological understanding which are present in infancy. That is, Taborda-Osorio and Cheries [ 19 ] argue that older children’s tendency to focus on internal features when reasoning about animate entities is rooted in two cognitive processes that emerge in the first year of life: a domain-general bias to represent kind membership based on non-obvious properties, and a domain-specific tendency to attribute physical insides to animate entities.…”

“…Instead, we favor the account recently put forth by Taborda-Osorio and Cheries [ 19 ] which proposes that that there are developmental precursors to later biological understanding which are present in infancy. That is, Taborda-Osorio and Cheries [ 19 ] argue that older children’s tendency to focus on internal features when reasoning about animate entities is rooted in two cognitive processes that emerge in the first year of life: a domain-general bias to represent kind membership based on non-obvious properties, and a domain-specific tendency to attribute physical insides to animate entities. Our findings support this proposition by demonstrating that young infants will use animacy cues to guide their attention towards the insides of an object within the first year of life, supporting the notion that a more sophisticated understanding of biological kinds may have its roots in certain cognitive biases present in early infancy.…”

“…The research described above demonstrates that preschoolers appreciate the importance of internal features for animates. A number of studies have demonstrated that this understanding emerges during infancy (see [ 19 ] for a review). For example, 8-month-olds expect self-propelled agents to possess insides, and exhibit surprise when an item exhibiting self-propulsion and agency is shown to be hollow [ 20 ].When the item has only one of these two properties (i.e., the item is self-propelled but lacks agency, or exhibits agency but not self-propulsion), infants do not appear to hold expectations regarding the item’s insides.…”

“…We tested infants ranging in age from 9 to 11 months, with an average age of 10 months, in light of recent evidence showing that 6.5- to 9.5-month-olds will use animacy cues to guide their expectations of an object’s insides [ 20 ]. Our motivation for testing 10-month-olds is guided by Taborda-Osorio and Cheries [ 19 ]’s recent proposal that infants’ bias to represent kind membership based on non-obvious properties, as well as to attribute insides to animate beings emerges during the first year of life. As reviewed above, however, little empirical research has directly addressed whether infants under 12 months attend to the insides of animates, with the exception of Setoh et al [ 20 ] who demonstrated that 8-month-olds expect self-propelled objects to have insides.…”