Julian Jara-Ettinger

Not So Innocent: Toddlers’ Inferences About Costs and Culpability

Adults’ social evaluations are influenced by their perception of other people’s competence and motivation: Helping when it is difficult to help is praiseworthy, and not helping when it is easy to help is reprehensible. Here, we look at whether children’s social evaluations are affected by the costs that agents incur. We found that toddlers can use the time and effort associated with goal-directed actions to distinguish agents, and that children prefer agents who incur fewer costs in completing a goal. When two agents refuse to help, children retain a preference for the more competent agent but infer that the less competent agent is nicer. These results suggest that children value agents who incur fewer costs, but understand that failure to engage in a low-cost action implies a lack of motivation. We propose that a naive utility calculus underlies inferences from the costs and rewards of goal-directed action and thereby supports social cognition.

Rational quantitative attribution of beliefs, desires and percepts in human mentalizing

Social cognition depends on our capacity for ‘mentalizing’, or explaining an agent’s behaviour in terms of their mental states. The development and neural substrates of mentalizing are well-studied, but its computational basis is only beginning to be probed. Here we present a model of core mentalizing computations: inferring jointly an actor’s beliefs, desires and percepts from how they move in the local spatial environment. Our Bayesian theory of mind (BToM) model is based on probabilistically inverting artificial-intelligence approaches to rational planning and state estimation, which extend classical expected-utility agent models to sequential actions in complex, partially observable domains. The model accurately captures the quantitative mental-state judgements of human participants in two experiments, each varying multiple stimulus dimensions across a large number of stimuli. Comparative model fits with both simpler ‘lesioned’ BToM models and a family of simpler non-mentalistic motion features reveal the value contributed by each component of our model.

Can processing demands explain toddlers’ performance in false-belief tasks?

Two-and-a-half-year-olds normally fail standard false-belief tasks. In the classic version, children have to say where a protagonist will look for an apple that, unbeknownst to her, was moved to a new location. Children under 4 generally predict that the protagonist will look for her apple in its current location, rather than where she left it. Setoh, Scott, and Baillargeon (1) argue that young children fail standard false-belief tasks because of their high processing demands, not because young children lack the necessary theory of mind. This processing-demands account is challenged by “low-inhibition tasks,” in which the apple is removed from the scene altogether (2): rather … [↵][1]1To whom correspondence should be addressed. Email: prubio{at}mit.edu. [1]: #xref-corresp-1-1

The Naïve Utility Calculus: Computational Principles Underlying Commonsense Psychology: (Trends in Cognitive Sciences 20, 589–604; July 19, 2016)

Due to an oversight in the preparation of this Feature Review article, the authors mistakenly labeled Figure 2 Panel E “Forego low-cost and high-cost plans”. The correct label for Figure 2 Panel E is “Forego low-reward and high-reward plans”. Figure 2 has been corrected in the article online. The correct version of the panel is also shown here.View Large Image | Download PowerPoint Slide

The Use of a Computer Display Exaggerates the Connection Between Education and Approximate Number Ability in Remote Populations

Piazza et al. reported a strong correlation between education and approximate number sense (ANS) acuity in a remote Amazonian population, suggesting that symbolic and nonsymbolic numerical thinking mutually enhance one another over in mathematics instruction. But Piazza et al. ran their task using a computer display, which may have exaggerated the connection between the two tasks, because participants with greater education (and hence better exact numerical abilities) may have been more comfortable with the task. To explore this possibility, we ran an ANS task in a remote population using two presentation methods: (a) a computer interface and (b) physical cards, within participants. If we only analyze the effect of education on ANS as measured by the computer version of the task, we replicate Piazza et al.’s finding. But importantly, the effect of education on the card version of the task is not significant, suggesting that the use of a computer display exaggerates effects. These results highlight the importance of task considerations when working with nonindustrialized cultures, especially those with low education. Furthermore, these results raise doubts about the proposal advanced by Piazza et al. that education enhances the acuity of the approximate number sense.

Children understand that agents maximize expected utilities.

A growing set of studies suggests that our ability to infer, and reason about, mental states is supported by the assumption that agents maximize utilities—the rewards they attain minus the costs they incur. This assumption enables observers to work backward from agents’ observed behavior to their underlying beliefs, preferences, and competencies. Intuitively, however, agents may have incomplete, uncertain, or wrong beliefs about what they want. More formally, agents try to maximize their expected utilities. This understanding is crucial when reasoning about others’ behavior: It dictates when actions reveal preferences, and it makes predictions about the stability of behavior over time. In a set of 7 experiments we show that 4- and 5-year-olds understand that agents try to maximize expected utilities, and that these responses cannot be explained by simpler accounts. In particular, these results suggest a modification to the standard belief/desire model of intuitive psychology. Children do not treat beliefs and desires as independent; rather, they recognize that agents have beliefs about their own desires and that this has consequences for the interpretation of agents’ actions.