Teleological beliefs about biological and nonbiological natural entities

Any given structure or event could be explained in one of two ways: mechanistically, or teleologically. Mechanistic explanations focus on the antecedent events which cause a particular structure or event to occur. Teleological explanations, on the other hand, describe structures or events with reference to the function that they serve. People often use teleological explanation to describe the world around them, and in many cases teleological explanation is not only useful, but justified (e.g., “he completed a PhD in order to work in research”). However, people sometimes use teleological explanation in ways that, although useful in allowing us to predict what will occur in the future, are perhaps not justified (e.g., “rivers flow downstream to get to the ocean”). This thesis focuses on the cognitive processes underlying this latter form of teleological explanation.

The overarching argument presented in this thesis, is that folk-teleological reasoning is based in an understanding, and over-extension, of thinking in terms of intentionality, and that the expression of teleological beliefs can be conceptualised within a dual-process framework. However, across nine studies, I show that this intention-based account of teleological reasoning is more nuanced than the existing literature suggests. First, an “understanding of intentionality” can mean that the natural world is understood as an artefact designed by an intending creator, or as an agent capable of intentional action. I show that both views independently predict acceptance of teleological explanations about biological and nonbiological natural entities, but that these represent two distinct pathways to teleological belief. Second, although the existing literature has strongly focused on the antecedents of teleological belief (i.e., developmental, and cognitive factors), I show that teleological beliefs about the natural world can have important consequences for how people respond to uncertainty and threat. Third, although non-experimental evidence suggests that the expression of teleological beliefs can be conceptualised within a dual-process framework, I show that a critical aspect of this dual-process perspective needs to be modified, such that effortful thought is not necessarily required to explicitly reject teleological explanations about biological and nonbiological natural entities. Finally, I show that not all teleological explanations are created equal. Although attributions of intentionality do positively predict acceptance of teleological explanations about biological and nonbiological natural entities, this is contingent upon a causal relationship between elements of the explanation. These findings provide a unified account of teleological reasoning that reconciles empirical psychological data within an existing philosophical account of biological function.