Great apes distinguish true from false beliefs in an interactive helping task

Understanding the behavior of others in a wide variety of circumstances requires an understanding of their psychological states. Humans’ nearest primate relatives, the great apes, understand many psychological states of others, for example, perceptions, goals, and desires. However, so far there is little evidence that they possess the key marker of advanced human social cognition: an understanding of false beliefs. Here we demonstrate that in a nonverbal (implicit) false-belief test which is passed by human 1-year-old infants, great apes as a group, including chimpanzees (Pan troglodytes), bonobos (Pan paniscus), and orangutans (Pongo abelii), distinguish between true and false beliefs in their helping behavior. Great apes thus may possess at least some basic understanding that an agent’s actions are based on her beliefs about reality. Hence, such understanding might not be the exclusive province of the human species.Publisher PDFPeer reviewe

Editorial: Learning in Social Context: The Nature and Profit of Living in Groups for Development

One of humans' most distinctive feature is their unique sociality. Research has shown that people are ready to use a variety of cues to draw distinctions between “us” and “them” (Over and Carpenter, 2012). Theories of social categorization share common assumptions: in-group bias may benefit an individual as it helps them to boost their own self-esteem (Tajfel and Turner, 1986) or provides an ideological ground for oppressing others (Sidanius and Pratto, 1993). Past research in developmental psychology has already provided insight into children's representations of the social world. It has been shown that infants as young as only a few months of age categorize others based on gender (Quinn et al., 2002). They even do so for language (Kinzler et al., 2007), which has been identified as a reliable indicator of group-membership for infants. While there is emergent evidence that already infants form “social categories,” little is known about the fact whether infants' social categories reflect an “in-group” preference per se, or a preference for people sharing traits with those in their environment. The central question of this research topic focused on the role of the ability to categorize social partners in the environment for the developing mind. More precisely, we wanted to see whether this ability influences epistemic development as well, beyond the enrichment of social-emotional competencies

A meta-analytic approach to the association between inhibitory control and parent-reported behavioral adjustment in typically-developing children: Differentiating externalizing and internalizing behavior problems

Impairments in inhibitory control (IC) are traditionally seen as a vital aspect in the emergence and course of maladaptive behavior across early childhood. However, it is currently unclear whether this view applies to both the externalizing and internalizing domain of parent-reported behavioral adjustment. Furthermore, past (meta-analytic) developmental research and theory characterizing this association have largely neglected the vast heterogeneity of IC measures and conceptualizations. The present meta-analyses examined the association of IC with parent-reported externalizing (N = 3160, 21 studies) and internalizing (N = 1758, 12 studies) behavior problems, assessed with the Child Behavior Checklist (CBCL), in non-clinical populations of children aged 2-8 years. They further investigated the moderating effects of a priori IC categorization, according to a recently proposed two-factor model of IC ("Strength/Endurance" account, Simpson & Carroll, 2019). In line with previous research in the clinical domain, the current results corroborate the notion of a robust, but small association between IC and externalizing behavior problems (r = -0.11) in early childhood. However, although frequently proposed in the literature, no significant linear association could be identified with internalizing behavior problems. Furthermore, in both meta-analyses, no significant moderating effects of IC categorization could be revealed. These findings enhance our knowledge about the cognitive underpinnings of early-emerging maladaptive behavior, indicating that different subtypes of IC are statistically related with externalizing, but not internalizing behavior problems. Overall, the small association of IC ability with behavior problems in non-clinical populations provokes broader questions about the role of IC in behavioral adjustment

Development and Plasticity of Cognitive Flexibility in Early and Middle Childhood

Cognitive flexibility, the ability to flexibly switch between tasks, is a core dimension of executive functions (EFs) allowing to control actions and to adapt flexibly to changing environments. It supports the management of multiple tasks, the development of novel, adaptive behavior and is associated with various life outcomes. Cognitive flexibility develops rapidly in preschool and continuously increases well into adolescence, mirroring the growth of neural networks involving the prefrontal cortex. Over the past decade, there has been increasing interest in interventions designed to improve cognitive flexibility in children in order to support the many developmental outcomes associated with cognitive flexibility. This article provides a brief review of the development and plasticity of cognitive flexibility across early and middle childhood (i.e., from preschool to elementary school age). Focusing on interventions designed to improve cognitive flexibility in typically developing children, we report evidence for significant training and transfer effects while acknowledging that current findings on transfer are heterogeneous. Finally, we introduce metacognitive training as a promising new approach to promote cognitive flexibility and to support transfer of training

Children’s understanding of first and third person perspectives in complement clauses and false belief tasks

De Villiers (2007) and others have claimed that children come to understand false beliefs as they acquire linguistic constructions for representing a proposition and the speaker’s epistemic attitude toward that proposition. In the current study, English-speaking children (N=64) of 3 and 4 years of age were asked to interpret propositional attitude constructions with a first-person or a third-person subject of the propositional attitude (e.g., I think the sticker is in the red box or The cow thinks the sticker is in the red box, respectively). They were also assessed for an understanding of their own and others’ false beliefs. We found that 4-year-olds showed a better understanding of both third-person propositional attitude constructions and false belief than their younger peers. No significant developmental differences were found for first-person propositional attitude constructions. The older children also showed a better understanding of their own than of others’ false beliefs. In addition, regression analyses suggest that the older children’s comprehension of their own false belief was mainly related to their understanding of third-person propositional attitude constructions. These results indicate that we need to take a closer look at the propositional attitude constructions that are supposed to support children’s false-belief reasoning. Children may come to understand their own and others’ beliefs in different ways, and this may affect both their use and understanding of propositional attitude constructions and their performance in various types of false-belief tasks

Corrigendum: Reduced mu power in response to unusual actions is context-dependent in 1-year-olds

During social interactions infants predict and evaluate other people’s actions. Previous behavioral research found that infants’ imitation of others’ actions depends on these evaluations and is context-dependent: 1-year-olds predominantly imitated an unusual action (turning on a lamp with one’s forehead) when the model’s hands were free compared to when the model’s hands were occupied or restrained. In the present study, we adapted this behavioral paradigm to a neurophysiological study measuring infants’ brain activity while observing usual and unusual actions via electroencephalography. In particular, we measured differences in mu power (6 – 8 Hz) associated with motor activation. In a between-subjects design, 12- to 14-month-old infants watched videos of adult models demonstrating that their hands were either free or restrained. Subsequent test frames showed the models turning on a lamp or a soundbox by using their head or their hand. Results in the hands-free condition revealed that 12- to 14-month-olds displayed a reduction of mu power in frontal regions in response to unusual and thus unexpected actions (head touch) compared to usual and expected actions (hand touch). This may be explained by increased motor activation required for updating prior action predictions in response to unusual actions though alternative explanations in terms of general attention or cognitive control processes may also be considered. In the hands-restrained condition, responses in mu frequency band did not differ between action outcomes. This implies that unusual head-touch actions compared to hand-touch actions do not necessarily evoke a reduction of mu power. Thus, we conclude that reduction of mu frequency power is context-dependent during infants’ action perception. Our results are interpreted in terms of motor system activity measured via changes in mu frequency band as being one important neural mechanism involved in action prediction and evaluation from early on

On Universal Tests for the Truth of World Views: Their Existence and Identifiability

In his book, Christian Apologetics, Norman Geisler proposes a universal test for the truth of world views. We examine this concept and find that it raises serious difficulties. This paper first presents some basic definitions for world view and truth-value of a world view, then studies the concept of a universal test for the truth of world views in light of these definitions. Geisler has proposed what amounts to a universal decision procedure to determine the truth-value of world views. We show that, in the general case, no such universal decision procedure exists. Whether or not such universal tests for truth exist within the framework of apologetics depends on the language and domain of discourse, but given the broad nature of the subject matter of apologetics, it is highly unlikely that they do exist. Finally, we consider the problem of identifying a universal test for truth, assuming, that one does exist, and prove that there is no guarantee that such a universal test for truth can ever be known, within the bounds of natural reason, by proving that there is no decision procedure to test for universal test for truth. These results lead to an open problem which we pose for apologetics. This paper makes use of new discoveries in logic spearheaded by Godel\u27s landmark Incompleteness Theorem in 1931. Since Aristotle, we have been learning that there are limits on the nature of truth. The recent discoveries in logic have shown that there is a difference between truth and the knowledge of truth, and that there are also limits on the nature of knowledge. The limits have nothing to do with who knows, but with how the knowing is done. The structure of knowledge turns out to be such that, for most (but not all) general systems of truth broad enough to include even the elementary truths of human experience, there is no effective procedural way to know all the truths in such systems as true. It appears that God has not only carefully ordered and structured truth, but He has also placed some fundamental limits on the nature of unaided human knowledge

Factive and nonfactive mental state attribution

Factive mental states, such as knowing or being aware, can only link an agent to the truth; by contrast, nonfactive states, such as believing or thinking, can link an agent to either truths or falsehoods. Researchers of mental state attribution often draw a sharp line between the capacity to attribute accurate states of mind and the capacity to attribute inaccurate or “reality-incongruent” states of mind, such as false belief. This article argues that the contrast that really matters for mental state attribution does not divide accurate from inaccurate states, but factive from nonfactive ones

Isolation of intact chloroplast for sequencing plastid genomes of five festuca species

Isolation of good quality chloroplast DNA (cpDNA) is a challenge in different plant species, although several methods for isolation are known. Attempts were undertaken to isolate cpDNA from Festuca grass species by using available standard protocols; however, they failed due to difficulties separating intact chloroplasts from the polysaccharides, oleoresin, and contaminated nuclear DNA that are present in the crude homogenate. In this study, we present a quick and inexpensive protocol for isolating intact chloroplasts from seven grass varieties/accessions of five Festuca species using a single layer of 30% Percoll solution. This protocol was successful in isolating high quality cpDNA with the least amount of contamination of other DNA. We performed Illumina MiSeq paired-end sequencing (2 × 300 bp) using 200 ng of cpDNA of each variety/accession. Chloroplast genome mapping showed that 0.28%–11.37% were chloroplast reads, which covered 94%–96% of the reference plastid genomes of the closely related grass species. This improved method delivered high quality cpDNA from seven grass varieties/accessions of five Festuca species and could be useful for other grass species with similar genome complexity

War Rations British Homemaking

Marabeth Paddock explains how British homemakers are solving war-time nutrition problems with ingenuit