Parental and familial factors influence numerous aspects of adolescents’ lives, including their physical activity level (PAL). The purpose of this study was to evaluate the changes in PAL which occurred during the COVID-19 pandemic, and to evaluate influence of sociodemographic and parental/familial factors on PAL levels before and during pandemic in adolescents from Bosnia and Herzegovina. The sample included 688 adolescents (15–18 years of age; 322 females) who were tested on two occasions: in January 2020 (baseline; before the COVID-19 pandemic) and in April 2020 (follow-up; during the COVID-19 pandemic lockdown). Variables included PAL (measured by the Physical Activity Questionnaire for Adolescents–PAQ-A) as well as sociodemographic-, parental-, and familial factors. A significant decline in PALs was recorded between baseline and follow-up (t-test: 11.88, p < 0.001). Approximately 50% of adolescents underwent sufficient PAL at baseline, while only 24% of them were achieving sufficient PAL at the time of follow-up measurement. Paternal education was positively correlated (OR (95%CI): baseline: 6.63 (4.58–9.96), follow-up: 3.33 (1.19–7.01)), while familial conflict was negatively correlated (baseline: 0.72 (0.57–0.90), follow-up: 0.77 (0.60–0.99)) with PALs before and during the pandemic. This study highlights the importance of the parent–child relationship and parental/familiar support in promoting physical activity both during regular life and during crises and health challenging situations like the COVID-19 pandemic.

– Eurasian jays ( Garrulus glandarius ) do not habitually use tools, yet they can be trained to solve object-dropping tasks, i.e., to insert a tool into an apparatus to release a food reward. Previous research suggests that these jays can learn a preference toward functional tools – objects allowing them to obtain a food reward placed inside an apparatus – according to their density (Cheke et al., 2011). However, it is not yet known whether they can also select functional tools (tool selectivity) according to other physical properties such as size and shape and use different kinds of tools to solve a similar task. Here we conducted three object-dropping experiments aimed at exploring these abilities in Eurasian jays. In Experiment 1, jays tended to select large stones as tools irrespective of the diameter of the apparatus. However, jays progressively developed a preference for the small tool, which was functional with both the wide and the narrow apparatuses. In Experiment 2, only vertically oriented long stones could fit into the narrow apparatus, whereas both long and round stones were functional with the wide apparatus. Jays showed a preference for the long stone and, with the narrow apparatus, tended to achieve the correct manipulation after one or more unsuccessful attempts. In Experiment 3, jays were able to use sticks and adopt a novel technique on the same object-dropping apparatus, thus providing the first evidence that Eurasian jays can use sticks as tools. Taken together, these results do not support the notion that tool selectivity abilities can be found in Eurasian jays but nonetheless show that these corvids can use different kinds of tools to solve similar tasks.

Previous research reported that corvids preferentially cache food in a location where no food will be available or cache more of a specific food in a location where this food will not be available. Here, we consider possible explanations for these prospective caching behaviours and directly compare two competing hypotheses. The Compensatory Caching Hypothesis suggests that birds learn to cache more of a particular food in places where that food was less frequently available in the past. In contrast, the Future Planning Hypothesis suggests that birds recall the ‘what–when–where’ features of specific past events to predict the future availability of food. We designed a protocol in which the two hypotheses predict different caching patterns across different caching locations such that the two explanations can be disambiguated. We formalised the hypotheses in a Bayesian model comparison and tested this protocol in two experiments with one of the previously tested species, namely Eurasian jays. Consistently across the two experiments, the observed caching pattern did not support either hypothesis; rather it was best explained by a uniform distribution of caches over the different caching locations. Future research is needed to gain more insight into the cognitive mechanism underpinning corvids’ caching for the future.

A major research area in non-human social cognition is the investigation of cooperative problem solving, i.e. the cognition involved in situations when animals cooperate with each other. Social cognition is thought to have evolved due to the demands of social living, and is often thought to present an adaptive specialisation for living in groups. A previous analysis of social learning, another area of social cognition, has highlighted how this has consequently led to two overarching biases in the literature: firstly, a bias towards testing only social species, and secondly, an a priori assumption that social learning is qualitatively different from learning involved in non-social situations. The problem of these biases may not restricted to social learning but be present also in other areas of social cognition research. Applying an equivalent analysis to cooperative problem solving shows that here too both biases are present. Firstly, empirical studies on cooperative problem solving primarily conducted with social species and species that exhibit cooperative behaviours in the wild. Secondly, the assumption that cooperative problem solving relies on a distinctly socialcognitive ability can, at least implicitly, be observed throughout the literature. Thismay be the result of confounding different components of the cognitive process involved in cooperation: what information is required to successfully cooperate and how this information is acquired. While the former needs to involve information about another individual, there is no indication that the latter is required to differ from any known, domain-general cognitive mechanism. These two biases make it difficult to systematically test whether and how cooperation differs between species, and as such impede investigations into the evolution of cooperative problem solving.

Twenty years after Povinelli’s “Folk Physics for Apes”, this paper assesses how researchers have made claims about animal physical cognition, and the statistical inferences that have been used to support them. These data are relevant in light of the current replicability issues facing science. We surveyed 116 published experiments from 63 papers on physical cognition, which included data from 43 different species of animals. Across these experiments most sample sizes were small, with often fewer than 10 animals being tested. However, in contrast to related psychological disciplines, we found that only 62% of our sample of physical cognition research made positive claims. This suggests that animal physical cognition does not have a strong publication bias towards positive results. Furthermore, we found evidence that researchers are making many true statistical inferences at the individual level, i.e. whether individual animals pass certain tests of physical cognition or not. In contrast, the strength of evidence of statistical effects at the group level was weaker and consistent with many effect sizes being overestimated. Overall, our analysis provides a cautiously optimistic analysis of reliability and bias in animal physical cognition research, however it is nevertheless likely that a non-negligible proportion of results will be difficult to replicate.

Scientific disciplines face concerns about replicability and statistical inference, and these concerns are also relevant in animal cognition research. This paper presents a first attempt to assess how researchers make and publish claims about animal physical cognition, and the statistical inferences they use to support them. We surveyed 116 published experiments from 63 papers on physical cognition, covering 43 different species. The most common tasks in our sample were trap-tube tasks (14 papers), other tool use tasks (13 papers), means-end understanding and string-pulling tasks (11 papers), object choice and object permanence tasks (9 papers) and access tasks (5 papers). This sample is not representative of the full scope of physical cognition research; however, it does provide data on the types of statistical design and publication decisions researchers have adopted. Across the 116 experiments, the median sample size was 7. Depending on the definitions we used, we estimated that between 44% and 59% of our sample of papers made positive claims about animals' physical cognitive abilities, between 24% and 46% made inconclusive claims, and between 10% and 17% made negative claims. Several failures of animals to pass physical cognition tasks were reported. Although our measures had low inter-observer reliability, these findings show that negative results can and have been published in the field. However, publication bias is still present, and consistent with this, we observed a drop in the frequency of p-values above .05. This suggests that some non-significant results have not been published. More promisingly, we found that researchers are likely making many correct statistical inferences at the individual-level. The strength of evidence of statistical effects at the group-level was weaker, and its p-value distribution was consistent with some effect sizes being overestimated. Studies such as ours can form part of a wider investigation into statistical reliability in comparative cognition. However, future work should focus on developing the validity and reliability of the measurements they use, and we offer some starting points.

Male Eurasian jays were previously reported to alter their food-sharing response in line with the specific satiety of their female partner. Here, we tested the flexibility of the same males’ food-sharing behavior by testing whether they can process information from contextual cues that predict the opposite pattern of food shared to that observed in previous studies. In Experiment 1, we manipulated the amount of food eaten by the females in a choice context before males shared with them. In Experiment 2, we manipulated the identity of the non-chosen food that was available in a choice context before males shared with the females. In both experiments, males showed flexibility in their sharing pattern in a comparison between the experimental and control conditions. In Experiment 1, this observed pattern appears to be based on the males’ response to the amount of food eaten by the female, and in Experiment 2, it appears to be based on the males’ response to the choice context in which the female’s eating took place. Although the experimental conditions in Experiments 1 and 2 were conceptual replications, the predicted pattern of food shared by the males was detected only in the latter. While replications are needed to test the generalizability and robustness of these results, the current study provides a first set of data in line with the hypothesis that the Eurasian jay males may be able to flexibly adjust their food-sharing behavior to contextual cues. Raw data are available at 10.5281/zenodo.3633986, and code and meta-data are available at https://osf.io/n9rcd/.

Background: Endurance training (ET) and resistance training (RT) are known to be effective in improving anthropometric/body composition and lipid panel indicators, but there is an evident lack of studies on differential effects of these two forms of physical exercise (PE). This study aimed to evaluate the differential effects of 8-week ET and RT among young adult women. Methods: Participants were women (n = 57; age: 23 ± 3 years; initial body height: 165 ± 6 cm; body mass: 66.79 ± 7.23 kg; BMI: 24.37 ± 2.57 kg/m2) divided into the ET group (n = 20), RT group (n = 19), and non-exercising control group (n = 18). All participants were tested for cardiovascular risk factors (CRF), including total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), triglycerides, glucose, and anthropometric/body composition (body mass, body mass index, skinfold measures, body fat %) at the beginning and at the end of the study. Over the 8 weeks, the ET group trained three times/week on a treadmill while the RT group participated in equal number of circuit weight training sessions. Both types of training were planned according to participants’ pre-study fitness status. Results: A two-factor analysis of variance for repeated measurements (“group” × “measurement”) revealed significant main effects for “measurement” in CRF. The “group × measurement” interaction was significant for CRF. The post-hoc analysis indicated significant improvements in CRF for RT and ET. No significant differential effects between RT and ET were evidenced. Conclusions: The results of this study evidence improvements of CRF in young adult women as a result of 8-week ET and RT. The lack of differential training-effects may be attributed to the fact that all participants underwent pre-study screening of their fitness status, which resulted in application of accurate training loads.

Jedno je od glavnih istraživačkih područja u socijalnoj kogniciji životinja kooperativno rješavanje problema, tj. kognicija kod međusobne suradnje životinja. Smatra se da je socijalna kognicija evoluirala zbog zahtjeva koje donosi život u grupama i često se drži adaptacijom za takav život. Analiza socijalnoga učenja, drugoga istraživačkog područja unutar socijalne kognicije, pokazala je da je ta pretpostavka u literaturi prouzročila dva problema. Prvo, postoji pristranost prema testiranju socijalnih vrsta, i drugo, postoji a priori pretpostavka da je socijalno učenje kvalitativno drugačije od individualnoga. Ta dva problema nisu nužno ograničena na socijalno učenje, nego mogu biti prisutna i u drugim poljima unutar istraživanja socijalne kognicije. Primjena slične analize na kooperativno rješavanje problema ukazuje da i u tome području postoje oba problema. Prvo, empirijska se istraživanja provode ponajprije na vrstama koje su socijalne i na onima koje pokazuju kooperativna ponašanja u divljini. Drugo, pretpostavka da se kooperativno rješavanje problema temelji na specifično socijalnim kognitivnim sposobnostima implicirana je u velikome dijelu literature. Moguće je da je to rezultat miješanja različitih komponenti unutar kognitivnoga procesa: koja je informacija potrebna za uspješnu kooperaciju i kako se ta informacija stječe. Dok prva komponenta mora uključivati informaciju o drugome pojedincu, ne postoji indikacija da se druga komponenta mora razlikovati od već poznatih, općenamjenskih mehanizama. Ta dva problema sprečavaju sistematsko ispitivanje razlika između vrsta i ometaju istraživanje evolucije kooperativnoga rješavanja problema.

In an open letter more than five years ago, a group of scientists called for adopting Registered Reports in all journals of the life sciences. This letter and subsequent efforts have yielded some notable success. At time of writing, 207 journals support the Registered Reports format, with many more currently considering its implementation. However, these numbers are still small in comparison to the many journals that rely exclusively on the traditional way of evaluating scientific quality. We, a group of over 250 scientists, want to emphatically reiterate the importance of accepting studies before the results are in. We call for all empirical journals in the social and life sciences to offer Registered Reports, alongside the traditional publication formats.

A prominent vein of comparative cognition research asks which cognitive abilities may be ascribed to different species. Here, we argue that the current structure of comparative cognition makes it near impossible to evaluate the accuracy of many of the claims produced by the field’s empirical research. We base this argument on six observations: i) the field is biased towards confirming more exceptional abilities in animals, ii) a likely high rate of false positive discovery, iii) the persistence of the bias towards more exceptional abilities, even in the presence of strong methodological criticism, iv) the absence of a formal method to assess evidence of absence of a cognitive ability, v) the ambiguity in definitions used to make claims, and vi) the small size of the research field. We then highlight how the widespread methodological and conceptual criticism in the comparative cognition literature does not facilitate scientific progress, rather it can impede it by creating an illusion of scientific rigour. Finally, we call for a reform of our research field that draws on recent developments in related fields and the Open Science movement.