Do wild New Caledonian crows (<Emphasis Type="Italic">Corvus moneduloides</Emphasis>) attend to the functional properties of their tools?

New Caledonian crows are the most proficient non-hominin tool manufacturers but the cognition behind their remarkable skills remains largely unknown. Here we investigate if they attend to the functional properties of the tools that they routinely use in the wild. Pandanus tools have natural barbs along one edge that enable them to function as hooking implements when the barbs face backwards from the working tip. In experiment 1 we presented eight crows with either a non-functional (‘upside-down’) or a functional pandanus tool in a baited hole. Four of the crows never flipped the tools. The behaviour of the four flipping birds suggested that they had a strategy of flipping a tool when it was not working. Observations of two of the eight crows picking up pandanus tools at feeding tables in the wild supported the lack of attention to barb direction. In experiment 2 we gave six of the eight crows a choice of either a barbed or a barbless pandanus tool. Five of the crows chose tools at random, which further supported the findings in experiment 1 that the crows paid little or no attention to the barbs. In contrast, a third experiment found that seven out of eight crows flipped non-functional stick tools significantly more than functional ones. Our findings indicate that the crows do not consistently attend to the presence or orientation of barbs on pandanus tools. Successful pandanus tool use in the wild seems to rely on behavioural strategies formed through associative learning, including procedural knowledge about the sequence of operations required to make a successful pandanus tool. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Effects of Applying the PETTLEP Model on Vividness and Ease of Imaging Movement

This study investigated the effects of applying elements of the PETTLEP model on vividness and ease of imaging movement. Forty participants (M age = 23.47 years, SD = 4.11) completed the Vividness of Movement Imagery Questionnaire when using PETTLEP imagery or traditional imagery. Results revealed significantly higher ease and vividness ratings for internal visual imagery (IVI) and kinesthetic imagery (KI) during the PETTLEP imagery condition compared to the more traditional imagery. No significant difference between conditions for external visual imagery emerged. Findings imply that incorporating PETTLEP elements during imagery enables greater ease and vividness of movement when using IVI and KI.     

Competing stimulus assessments: A systematic review

The current review summarizes the literature on competing stimulus assessments (CSAs). CSAs are pretreatment assessments designed to systematically identify stimuli that reduce problem behavior (PB), ostensibly through reinforcer competition or substitution. We report on the participant characteristics, outcomes, and predictive validity of published CSAs that included (a) no-stimulus control trial(s), (b) test trials during which each stimulus was available singly and noncontingently, and (c) measurement of PB and stimulus engagement or contact. Results showed that CSAs have broad utility across a variety of topographies and functions of PB. In the majority of CSA applications for which extended analyses, or validations, were performed, stimuli shown to reduce PB during the CSA produced similar reductions during extended analysis. This was the case regardless of topography or function of PB, or whether the stimuli were assumed to be “matched” to the stimulation thought to be produced by PB. Implications for future research are discussed.     

Retracted: The Three-Step Theory of Suicide: An Independent Replication and Conceptual Extension

Retraction: Christopher R. Hagan PhD, Jennifer J. Muehlenkamp PhD, “The Three-Step Theory of Suicide: An Independent Replication and Conceptual Extension,” Suicide and Life-Threatening Behavior, Wiley, © American Association of Suicidology The above article, published online on 30 September 2019 in Wiley Online Library ( wileyonlinelibrary.com ), has been retracted by agreement between the authors, the journal Editor in Chief, Thomas Joiner, PhD, and John Wiley and Sons Ltd. The retraction has been agreed due to errors in variable calculation and a post-publication reviewer's concerns that some analyses did not accurately test the theoretical model. An updated version of this article will soon undergo review for publication at Suicide and Life-Threatening Behavior, and if accepted for publication, will be accompanied by an editorial from the Editor-in-Chief.     

A Sociobiological Analysis of Namesaking Patterns in 322 American Families1

A study of the naming patterns used for 648 children in 322 American families provided mixed support for a number of hypotheses that are derived from the propositions that namesaking (the naming of a child after another person) functions as advertisement of genetic kinship when it may be in doubt and as a strategy to procure future investment of resources from the father and other relatives. Males and second-born children with older sisters were more likely to be namesaked, and birth order was a significant predictor of the probability of being namesaked for males. First-borns were more likely to be named after a patrilineal relative, but there was no tendency for children born early in a marriage to be namesaked more frequently than children born after many years of marriage. Parents who themselves were namesaked were more likely to namesake their own children.     

Around the world,adolescence is a time of heightened sensation seeking and immature self‐regulation

The dual systems model of adolescent risk‐taking portrays the period as one characterized by a combination of heightened sensation seeking and still‐maturing self‐regulation, but most tests of this model have been conducted in the United States or Western Europe. In the present study, these propositions are tested in an international sample of more than 5000 individuals between ages 10 and 30 years from 11 countries in Africa, Asia, Europe and the Americas, using a multi‐method test battery that includes both self‐report and performance‐based measures of both constructs. Consistent with the dual systems model, sensation seeking increased between preadolescence and late adolescence, peaked at age 19, and declined thereafter, whereas self‐regulation increased steadily from preadolescence into young adulthood, reaching a plateau between ages 23 and 26. Although there were some variations in the magnitude of the observed age trends, the developmental patterns were largely similar across countries.     

On the relation between theory of mind and executive functioning: A developmental cognitive neuroscience perspective

Theory of mind (ToM) and executive functioning (EF) show marked interrelatedness across childhood, and developmental psychologists have long been interested in understanding the nature of this association. The present review addresses this issue from a cognitive neuroscience perspective by exploring three hypotheses regarding their functional overlap: (1) ToM relies on EF (EF→ToM); (2) EF relies on ToM (ToM→EF); and (3) ToM and EF are mutually related, owing to shared neural structures or networks (ToM?EF). Drawing on evidence from normative brain development, neurodevelopmental and neurodegenerative diseases, patient lesion studies, and brain-imaging studies, we suggest that only a strict version of the ToM?EF proposal of complete neural overlap can be confidently ruled out on the basis of existing evidence. The balance of evidence suggests that separable neurobiological mechanisms likely underlie ToM and EF, with shared mechanisms for domain-general processing that support both abilities. We highlight how future studies may empirically substantiate the nature of the ToM–EF relationship using various biobehavioral approaches.