Six-Month-Old Infants Predict Agents' Goal-Directed Actions on Occluded Objects

"Catastrophic" set size limits on infants' capacity to represent objects: A systematic review and Bayesian meta-analysis

Decades of research has revealed that humans can concurrently represent small quantities of three-dimensional objects as those objects move through space or into occlusion. For infants (but not older children or adults), this ability apparently comes with a significant limitation: when the number of occluded objects exceeds three, infants experience what has been characterized as a "catastrophic" set size limit, failing to represent even the approximate quantity of the hidden array. Infants' apparent catastrophic representational failures suggest a significant information processing limitation in the first years of life, and the evidence has been used as support for prominent theories of the development of object and numerical cognition. However, the evidence for catastrophic failure consists of individual small-n experiments that use null hypothesis significance testing to obtain null results (i.e., p > 0.05). Whether catastrophic representational failures are robust or reliable across studies, methods, and labs is not known. Here we report a systematic review and Bayesian meta-analysis to examine the strength of the evidence in favor of catastrophic representational failures in infancy. Our analysis of 22 experiments across 12 reports, with a combined total of n = 367 infants aged 10-20 months, revealed strong support for the evidence for catastrophic set size limits. A complementary analysis found moderate support for infants' success when representing fewer than four objects. We discuss the implications of our findings for theories of object and numerical cognitive development. RESEARCH HIGHLIGHTS: Previous work has suggested that infants are unable to concurrently represent four or more objects-a "catastrophic" set size limit. We reviewed this work and conducted a Bayesian meta-analysis to examine the robustness of this limit across individual small-n experiments. We found strong support for the evidence for catastrophic set size limits, and moderate support for infants' success when representing fewer than four objects.

Objects in a social world: Infants' object representational capacity limits are shaped by objects' social relevance

Several decades of research have revealed consistent signature limits on infants' ability to represent objects. However, these signature representational limits were established with methods that often removed objects from their most common context. In infants' everyday lives, objects are very often social artifacts: they are the targets of agents' goal-directed actions, communications, and beliefs, and may have social content or relevance themselves. In this chapter, we explore the relationship between infants' object representational capacity limits and their processing of the social world. We review evidence that the social content and context of objects can shift infants' object representational limits. We discuss how taking the social world into account can yield more robust and ecologically valid estimates of infants' early representational capacities.

Inferring hidden objects from still and communicative onlookers at 8, 14, and 36 months of age

The current study investigated across five eye-tracking experiments children's developing skill of adopting others' referential perspective (Level 1 perspective taking) and to what extent it involves automatic processes or requires ostensive communicative cues. Three age groups (8-, 14-, and 36-month-olds) were tested on their expectation of an object appearing behind one of two peripheral occluders. A centrally presented person in profile either provided an ostensive communicative pointing cue or sat still, oriented to one of the two occluders. The 14-month-olds anticipated the hidden object when the onlooker had communicatively pointed to the location, as revealed by faster target detection in congruent trials (latency effect) and longer dwell times to the empty side in incongruent trials (violation-of-expectation effect). This was not the case when a still person was only oriented to one side. Adding emotional expressions to the still person (Experiment 2) did not help to produce the effects. However, at 36 months of age (Experiment 3), children showed both effects for the still person. The 8-month-olds did not show the violation-of-expectation effect for communicative pointing (Experiment 4) or for a matched abbreviated reach (Experiment 5b), showing it only for a complete reach behind the occluder (Experiment 5a), although they were faster to detect the congruent object in Experiment 4 and 5a. Findings reveal that automatic perspective taking develops after communicative perspective taking and that communicative perspective taking is a developmental outcome of the first year of life. The developmental pattern suggests a continuous social construction process of perspective-taking skills.