Limits on simulation approaches in intuitive physics.

A popular explanation of the human ability for physical reasoning is that it depends on a sophisticated ability to perform mental simulations. According to this perspective, physical reasoning problems are approached by repeatedly simulating relevant aspects of a scenario, with noise, and making judgments based on aggregation over these simulations. In this paper, we describe three core tenets of simulation approaches, theoretical commitments that must be present in order for a simulation approach to be viable. The identification of these tenets threatens the plausibility of simulation as a theory of physical reasoning, because they appear to be incompatible with what we know about cognition more generally. To investigate this apparent contradiction, we describe three experiments involving simple physical judgments and predictions, and argue their results challenge these core predictions of theories of mental simulation.

Broken Physics: A Conjunction-Fallacy Effect in Intuitive Physical Reasoning.

One remarkable aspect of human cognition is our ability to reason about physical events. This article provides novel evidence that intuitive physics is subject to a peculiar error, the classic conjunction fallacy, in which people rate the probability of a conjunction of two events as more likely than one constituent (a logical impossibility). Participants viewed videos of physical scenarios and judged the probability that either a single event or a conjunction of two events would occur. In Experiment 1 (n = 60), participants consistently rated conjunction events as more likely than single events for the same scenes. Experiment 2 (n = 180) extended these results to rule out several alternative explanations. Experiment 3 (n = 100) generalized the finding to different scenes. This demonstration of conjunction errors contradicts claims that such errors should not appear in intuitive physics and presents a serious challenge to current theories of mental simulation in physical reasoning.

Computational limits don't fully explain human cognitive limitations.

The project of justifying all the limits and failings of human cognition as inevitable consequences of strategies that are actually "optimal" relative to the limits on computational resources available may have some value, but it is far from a complete explanation. It is inconsistent with both common observation and a large body of experimentation, and it is of limited use in explaining human cognition.

Causal generative models are just a start.

Human reasoning is richer than Lake et al. acknowledge, and the emphasis on theories of how images and scenes are synthesized is misleading. For example, the world knowledge used in vision presumably involves a combination of geometric, physical, and other knowledge, rather than just a causal theory of how the image was produced. In physical reasoning, a model can be a set of constraints rather than a physics engine. In intuitive psychology, many inferences proceed without detailed causal generative models. How humans reliably perform such inferences, often in the face of radically incomplete information, remains a mystery.

How robust are probabilistic models of higher-level cognition?

An increasingly popular theory holds that the mind should be viewed as a near-optimal or rational engine of probabilistic inference, in domains as diverse as word learning, pragmatics, naive physics, and predictions of the future. We argue that this view, often identified with Bayesian models of inference, is markedly less promising than widely believed, and is undermined by post hoc practices that merit wholesale reevaluation. We also show that the common equation between probabilistic and rational or optimal is not justified.

A study of rural church health promotion environments: leaders' and members' perspectives.

This study examined the beliefs of church leaders about health and associations between these beliefs and the church health promotion environment (CHPE). Perceptions of the CHPE by leaders and members of the same churches were also compared. Interviews were conducted with pastors (n = 40) and members (n = 96) of rural churches. They were Baptist (60%), and 57.5% were predominantly White, while 42.5% were Black. Leaders' beliefs regarding talking about health topics in sermons were associated with the presence of health messages in the church. There was also a significant association between leaders' beliefs about members' receptivity to health messages and the presence of messages in the church. Leaders' and members' perceptions of the CHPE were discordant. While some leaders' beliefs may be related to the CHPE, other factors may explain why programs and policies exist in some churches and not others.

Unanswerable Questions About Images and Texts.

Questions about a text or an image that cannot be answered raise distinctive issues for an AI. This note discusses the problem of unanswerable questions in VQA (visual question answering), in QA (textual question answering), and in AI generally.