Children's understanding of death as the cessation of agency: a test using sleep versus death

Abstract

An important problem faced by children is discriminating between entities capable of goal-directed action, i.e. intentional agents, and non-agents. In the case of discriminating between living and dead animals, including humans, this problem is particularly difficult, because of the large number of perceptual cues that living and dead animals share. However, there are potential costs of failing to discriminate between living and dead animals, including unnecessary vigilance and lost opportunities from failing to realize that an animal, such as an animal killed for food, is dead. This might have led to the evolution of mechanisms specifically for distinguishing between living and dead animals in terms of their ability to act. Here we test this hypothesis by examining patterns of inferences about sleeping and dead organisms by Shuar and German children between 3 and 5-years old. The results show that by age 4, causal cues to death block agency attributions to animals and people, whereas cues to sleep do not. The developmental trajectory of this pattern of inferences is identical across cultures, consistent with the hypothesis of a living/dead discrimination mechanism as a reliably developing part of core cognitive architecture.

Introduction

Nearly a century of research has documented that death is a concept that is difficult for children to grasp (Carey, 1985, Nagy, 1948, Piaget, 1929; Speece and Brent, 1984, Speece and Brent, 1996). That this is so should not, perhaps, be surprising, because death is an ontologically strange phenomenon that poses difficult perceptual and conceptual challenges (Boyer, 2001). Perceptually, the challenge lies in the vast number of cues that living and dead things share. The transition from life to death is momentary, and may be perceptually quite difficult to detect. Conceptually, the challenge lies in the fact that death is one of the few cases in which an object crosses a major ontological boundary: in this case, the boundary between living things and non-living things. Given these considerations, the data documenting children's struggle to grasp the ontological nuances of death, a struggle that lasts well into late childhood and perhaps into adulthood, make sense (for reviews, see Slaughter et al., 1999, Speece and Brent, 1984).

From a theoretical perspective, prolonged and individually variable trajectories of conceptual development are expected in domains for which there is no core architecture, i.e. for which there are no mechanisms dedicated to the development of a conceptual apparatus according to a reliable developmental schedule (Leslie, 1994, Leslie, 1988). In such cases, possession of the appropriate principles necessary for inference in the domain depends critically on acquisition of relevant knowledge (Johnson & Carey, 1998). This is often described in terms of “theory change” (Carey, 1985, Gopnik and Meltzoff, 1997). Carey and colleagues (Carey, 1985, Johnson and Carey, 1998, Slaughter et al., 1999) have proposed just such a theory change account of death understanding. Under this account, young children begin with no core architecture to provide them with the relevant inferential principles for understanding death. This is because children do not yet possess a folk biology, i.e. an understanding of the causal mechanisms, or biological functions, that sustain life.

There are a variety of studies consistent with the theory change view. For example, Johnson and Carey (1998) found that individuals with Williams syndrome, who are developmentally impaired in their acquisition of a mature folk biology, perform poorly relative to controls on measures of death understanding that rely on folk biology, including standard tests of understanding of the four classical components of the death concept (see Speece and Brent, 1984, Speece and Brent, 1996). Several other studies support the proposal that understanding biological processes as having a life-sustaining function is important for later-developing aspects of death understanding (Carey, 1985, Slaughter et al., 1999, Slaughter and Lyons, 2003; see also Inagaki & Hatano, 2002, for a discussion of the development of a “vitalist” folk biology).

The understanding of death has many facets. Here, we do not wish to dispute the proposal that acquisition of theory-like knowledge may be important for understanding death specifically as the cessation of the biological processes that sustain life. Rather, we wish to propose that at least one aspect of death understanding—the understanding of death as the cessation of agency—is subserved by early developing core architecture: namely, the agency system, an early-developing inference system dedicated to understanding and predicting the behavior of intentional agents (Johnson, 2000, Leslie, 1994). This proposal differs from previous proposals that have suggested that there is no core architecture specifically subserving death understanding (Carey, 1985). We suggest, on the contrary, that the agency detection system (Johnson, 2000, Leslie, 1994, Rakison and Poulin-Dubois, 2001, Scholl and Tremoulet, 2000) contains, as part of its proper domain, procedures for discriminating living animals (agents) from dead ones. Here we sketch the principle features of this proposal, and offer an empirical test of some of its key predictions.