Limited spread of innovation in a wild parrot, the kea (Nestor notabilis)

In the local population of kea in Mount Cook Village, New Zealand, some keas open the lids of rubbish bins with their bill to obtain food scraps within. We investigated the extent to which this innovation has spread in the local population, and what factors limit the acquisition of bin opening. Only five males of 36 individually recognised birds were observed to have performed successful bin opening. With one exception there were always other keas present, watching successful bin opening. Seventeen additional individuals were seen to have benefitted from lid opening. Their foraging success was less than that of the bin openers. Social status of bin openers did not differ from scrounging males. Among the individuals that were regularly seen at the site of the bins but were not successful in bin opening, social status and the ratio of feeding directly from open bins correlated with the amount of opening attempts. We conclude that scrounging facilitated certain behavioural aspects of bin opening rather than inhibiting them. The fact that only 9% of opening attempts were successful, and the long period of time required to increase efficiency in lid opening shows that mainly individual experience, and to a lesser extent insight and social learning, play key roles in acquisition of the opening technique. The results indicate that the spread of innovative solutions of challenging mechanical problems in animals may be restricted to only a few individuals.     

Ethical considerations for research and treatment with runaway and homeless adolescents

Ethical considerations for working with runaway and homeless youth in research and treatment settings are presented. Issues of parents' and adolescents' consent for research and treatment are discussed, with particular attention given to the lack of explicit guidelines for working with abused and neglected youth. The principles of beneficence and justice are discussed as they apply to intervening with a high-risk, multiproblem population. The authors offer a rationale for allowing adolescents to self-consent to research and treatment. They argue that in many circumstances, requiring parental consent may not be in the youth's best interest and may preclude his or her participation in treatment and research programs.     

Attaining personal goals: self-concordance plus implementation intentions equals success

The present article includes separate meta-analyses showing that self-concordance and implementation intentions are significantly positively associated with goal progress. Study 1 confirmed the positive relations of both self-concordance and implementation intentions to weekend goal progress. Study 2 confirmed the positive relation of self-concordance with monthly progress on New Year's resolutions but failed to find a direct benefit for implementation intentions. Both studies, however, obtained a significant interaction effect indicating that goal self-concordance and implementation intentions combined synergistically to facilitate goal progress. The article also reports a meta-analysis and results from the 2 studies that demonstrated that goal progress was associated with improved affect over time.     

Interpopulation variation in the risk-related decisions of <Emphasis Type="Italic">Portia labiata</Emphasis>, an araneophagic jumping spider (Araneae,Salticidae), during predatory sequences with spitting spiders

The extent to which decision-making processes are constrained in animals with small brains is poorly understood. Arthropods have brains much smaller and simpler than those of birds and mammals. This raises questions concerning limitations on how intricate the decision-making processes might be in arthropods. At Los Ba?os in the Philippines, Scytodes pallidus is a spitting spider that specialises in preying on jumping spiders, and Portia labiata is a jumping spider that preys on S. pallidus. Scytodid spit comes from the mouth, and egg-carrying females are less dangerous than eggless scytodids because the female uses her chelicerae to hold her eggs. Held eggs block her mouth, and she has to release them before she can spit. The Los Ba?os P. labiata sometimes adjusts its tactics depending on whether the scytodid encountered is carrying eggs or not. When pursuing eggless scytodids, the Los Ba?os P. labiata usually takes detour routes that enable it to close in from behind (away from the scytodid's line of fire). However, when pursuing egg-carrying scytodids, the Los Ba?os P. labiata sometimes takes faster direct routes to reach these safer prey. The Los Ba?os P. labiata apparently makes risk-related adjustments specific to whether scytodids are carrying eggs, but P. labiata from Sagada in the Philippines (allopatric to Scytodes) fails to make comparable risk-related adjustments.     

Cross-language influences: translation status affects intraword sense relatedness

Many words have more than one meaning, and these meanings vary in their degree of relatedness. In the present experiment, we examined whether this degree of relatedness is influenced by whether or not the two meanings share a translation in a bilingual’s other language. Native English speakers with Spanish as a second language (i.e., English-Spanish bilinguals) and native Spanish speakers with English as a second language (i.e., Spanish-English bilinguals) were presented with pairs of phrases instantiating different senses of ambiguous English words (e.g., dinner date–expiration date) and were asked to decide whether the two senses were related in meaning. Critically, for some pairs of phrases, a single Spanish translation encompassed both meanings of the ambiguous word (joint-translation condition; e.g., mercado in Spanish refers to both a flea market and the housing market), but for others, each sense corresponded to a different Spanish translation (split-translation condition; e.g., cita in Spanish refers to a dinner date, but fecha refers to an expiration date). The proportions of “yes” (related) responses revealed that, relative to monolingual English speakers, Spanish–English bilinguals consider joint-translation senses to be less related than split-translation senses. These findings exemplify semantic cross-language influences from a first to a second language and reveal the semantic structure of the bilingual lexicon.     

Beginning adult L2 learners' sensitivity to morphosyntactic violations: A self-paced reading study

This study investigated beginning adult second language (L2) learners' sensitivity to L2 morphosyntactic violations as a function of cross-language similarity. Online sensitivity was indexed by self-paced reading times at: (1) the critical word at which the violation could first be detected, (2) the post-critical word, and (3) the sentence-final word. In conditions in which morphosyntactic marking systems were similar or different in L1 and L2, reading times on the critical word were slower when it cued a violation than when it did not; however, this sensitivity was not apparent in a construction unique to L2. Slower reading times to violations spilled over onto the post-critical word. Cross-language similarity also influenced sentence-final word reading times. Despite this online sensitivity, post-sentence grammaticality judgements were generally poor. However, these judgements were influenced by morphosyntactic markings on words after the critical word, suggesting that learners can make use of this information.     

Adolescent-specific patterns of behavior and neural activity during social reinforcement learning

Humans are sophisticated social beings. Social cues from others are exceptionally salient, particularly during adolescence. Understanding how adolescents interpret and learn from variable social signals can provide insight into the observed shift in social sensitivity during this period. The present study tested 120 participants between the ages of 8 and 25 years on a social reinforcement learning task where the probability of receiving positive social feedback was parametrically manipulated. Seventy-eight of these participants completed the task during fMRI scanning. Modeling trial-by-trial learning, children and adults showed higher positive learning rates than did adolescents, suggesting that adolescents demonstrated less differentiation in their reaction times for peers who provided more positive feedback. Forming expectations about receiving positive social reinforcement correlated with neural activity within the medial prefrontal cortex and ventral striatum across age. Adolescents, unlike children and adults, showed greater insular activity during positive prediction error learning and increased activity in the supplementary motor cortex and the putamen when receiving positive social feedback regardless of the expected outcome, suggesting that peer approval may motivate adolescents toward action. While different amounts of positive social reinforcement enhanced learning in children and adults, all positive social reinforcement equally motivated adolescents. Together, these findings indicate that sensitivity to peer approval during adolescence goes beyond simple reinforcement theory accounts and suggest possible explanations for how peers may motivate adolescent behavior.     

Maternal Mental Health and Child Adjustment Problems in Response to the COVID-19 Pandemic in Families Experiencing Economic Disadvantage

Research on Child and Adolescent Psychopathology - Parents living in low-income contexts shouldered disproportionate hardships during the COVID-19 pandemic with consequences to maternal mental...     

The impact of ignoring multiple membership data structures in multilevel models

This study compared the use of the conventional multilevel model (MM) with that of the multiple membership multilevel model (MMMM) for handling multiple membership data structures. Multiple membership data structures are commonly encountered in longitudinal educational data sets in which, for example, mobile students are members of more than one higher-level unit (e.g., school). While the conventional MM requires the user either to delete mobile students' data or to ignore prior schools attended, MMMM permits inclusion of mobile students' data and models the effect of all schools attended on student outcomes. The simulation study identified underestimation of the school-level predictor coefficient, as well as underestimation of the level-two variance component with corresponding overestimation of the level-one variance when multiple membership data structures were ignored. Results are discussed along with limitations and ideas for future MMMM methodological research as well as implications for applied researchers.     

The importance of "what": Infants use featural information to index events

Dynamic spatial indexing is the ability to encode, remember, and track the location of complex events. For example, in a previous study, 6-month-old infants were familiarized to a toy making a particular sound in a particular location, and later they fixated that empty location when they heard the sound presented alone (Journal of Experimental Psychology: General, 2004, Vol. 133, pp. 46-62). The basis and developmental trajectory of this ability are currently unclear. We investigated dynamic spatial indexing across the first year after birth and tested the hypothesis that the structure of visual cues supports infants' learning of sound and location associations. In our study, 3-, 6-, and 10-month-olds were tested in a dynamic spatial indexing eye movement paradigm that paired two sounds with two locations. In one condition, these were reliably paired with two sets of visual features (two toys condition), replicating the original studies. We also presented a single set of visual cues in both locations (one toy condition) and multiple sets of visual features in both locations (six toys condition). Infants from 3months of age onward showed evidence of dynamic spatial indexing in the two toys condition, but only the 10-month-olds succeeded in the one toy and six toys conditions. We argue that this may reflect a broader developmental trajectory, whereby infants first make use of multiple cue integration but with age are able to learn from a narrow set of cues.