Journal articles
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Kenward B, Berggren M, Kitazaki M, Itakura S, Kanakogi Y, 'Implicit social associations for geometric-shape agents more strongly influenced by visual form than by explicitly identified social actions'
Psychologia (2019)
ISSN: 0033-2852 eISSN: 1347-5916
Abstract Studies of infants' and adults' social cognition frequently use geometric-shape agents such as coloured squares and circles, but the influence of agent visual-form on social cognition has been little investigated. Here, although adults gave accurate explicit descriptions of interactions between geometric-shape aggressors and victims, implicit association tests for dominance and valence did not detect tendencies to encode the shapes’ social attributes on an implicit level. With regard to valence, the lack of any systematic implicit associations precludes conclusive interpretations. With regard to dominance, participants implicitly associated a yellow square as more dominant than a blue circle, even when the true relationship was the reverse of this and was correctly explicitly described by participants. Therefore, although explicit dominance judgements were strongly influenced by observed behaviour, implicit dominance associations were more clearly influenced by preconceived associations between visual form and social characteristics. This study represents a cautionary tale for those conducting experiments using geometric-shape agents.
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Kenward B, Pilling M, 'The now-moment is believed privileged because now is when happening is experienced (Commentary on BBS target article Thinking in and about time, by Hoerl and McCormack)'
Behavioral and Brain Sciences (2019)
ISSN: 0140-525X eISSN: 1469-1825
Abstract Hoerl and McCormack (H&M) risk misleading about the cognitive underpinnings of the belief in a privileged now-moment because they do not explicitly acknowledge that the sense of existing in the now-moment is an intrinsically temporally dynamic one. The sense of happening that is exclusive to the now-moment is a better candidate for the source of belief in a privileged now.
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Juvrud J, Bakker M, Kaduk K, DeValk JM, Gredebäck G, Kenward B, 'Longitudinal continuity in understanding and production of giving-related behavior from infancy to childhood'
Child Development 90 (2) (2019) pp.e182-e191
ISSN: 0009-3920 eISSN: 1467-8624
Abstract Infants have an early understanding of giving (the transfer of an item by one agent to another), but little is known about individual differences in these abilities or their developmental outcomes. Here, 9‐month‐olds (N = 59) showing clearer neural processing (Event‐related potential, ERP) of a give‐me gesture also evidenced a stronger reaction (pupil dilation) to an inappropriate response to a give‐me gesture, and at 2 years were more likely to give in response to a give‐me gesture. None of the differences in understanding and production of giving‐related behaviors were associated with other sociocognitive variables investigated: language, gaze‐following, and nongiving helping. The early developmental continuity in understanding and production of giving behavior is consistent with the great importance of giving for humans throughout the life span.
Website
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Kenward B, Koch F, Forssman L, Brehm J, Tidemann I, Sundqvist A, Marciszko C, Hermansen TK, Heimann M, Gredebäck G, 'Saccadic reaction times in infants and adults: spatiotemporal factors, gender, and inter-laboratory variation'
Developmental Psychology 53 (9) (2017) pp.1750-1764
ISSN: 0012-1649
Abstract Saccade latency is widely used across infant psychology to investigate infants’understanding of events. Interpreting particular latency values requires knowledge of standard saccadic reaction times, but there is no consensus as to typical values. This study provides standard estimates of infants’ (n=194, ages 9 to 15 months) saccadic reaction times under a range of different spatiotemporal conditions. To investigate the reliability of such standard estimates, data is collected at four laboratories in three countries. Results indicate that reactions to the appearance of a new object are much faster than reactions to the deflection of a currently fixated moving object; upward saccades are slower than downward or horizontal saccades; reactions to more peripheral stimuli are much slower; and this slowdown is greater for boys than girls. There was little decrease in saccadic reaction times between 9 and 15 month, indicating that the period of slow development which is protracted into adolescence begins in late infancy. Except for appearance and deflection differences, infant effects were weak or absent in adults (n=40). Latency estimates and spatiotemporal effects on latency were generally consistent across laboratories, but a number of lab differences in factors such as individual variation were found. Some but not all differences were attributed to minor procedural differences, highlighting the importance of replication. Confidence intervals (95%) for infants’ median reaction latencies for appearance stimuli were 242 – 250 ms and for deflection stimuli 350 – 367 ms.
Website
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Shutts K, Kenward B, Falk H, Ivegran A, Fawcett C, 'Early preschool environments and gender: Effects of gender pedagogy in Sweden'
Journal of Experimental Child Psychology 162 (2017) pp.1-17
ISSN: 0022-0965 eISSN: 1096-0457
Abstract To test how early social environments affect children’s consideration of gender, 3- to 6-year-old children (N = 80) enrolled in gender-neutral or typical preschool programs in the central district of a large Swedish city completed measures designed to assess their gender-based social preferences, stereotypes, and automatic encoding. Compared with children in typical preschools, a greater proportion of children in the gender-neutral school were interested in playing with unfamiliar other-gender children. In addition, children attending the gender-neutral preschool scored lower on a gender stereotyping measure than children attending typical preschools. Children at the gender-neutral school, however, were not less likely to automatically encode others’ gender. The findings suggest that gender-neutral pedagogy has moderate effects on how children think and feel about people of different genders but might not affect children’s tendency to spontaneously notice gender.Website
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Forslund T, Kenward B, Granqvist P, Gredebäck G, Brocki KC, 'Diminished ability to identify facial emotional expressions in children with disorganized attachment representations'
Developmental Science 20 (6) (2017)
ISSN: 1363-755X
Abstract The development of children's ability to identify facial emotional expressions has long been suggested to be experience dependent, with parental caregiving as an important influencing factor. This study attempts to further this knowledge by examining disorganization of the attachment system as a potential psychological mechanism behind aberrant caregiving experiences and deviations in the ability to identify facial emotional expressions. Typically developing children (N = 105, 49.5% boys) aged 6–7 years (M = 6 years 8 months, SD = 1.8 months) completed an attachment representation task and an emotion identification task, and parents rated children's negative emotionality. The results showed a generally diminished ability in disorganized children to identify facial emotional expressions, but no response biases. Disorganized attachment was also related to higher levels of negative emotionality, but discrimination of emotional expressions did not moderate or mediate this relation. Our novel findings relate disorganized attachment to deviations in emotion identification, and therefore suggest that disorganization of the attachment system may constitute a psychological mechanism linking aberrant caregiving experiences to deviations in children's ability to identify facial emotional expressions. Our findings further suggest that deviations in emotion identification in disorganized children, in the absence of maltreatment, may manifest in a generally diminished ability to identify emotional expressions, rather than in specific response biases.Website
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Kenward B, Osth T, 'Five-Year-Olds Punish Antisocial Adults'
Aggressive Behavior 41 (5) (2015) pp.413-420
ISSN: 0096-140X eISSN: 1098-2337
Abstract
The human tendency to impose costs on those who have behaved antisocially towards third parties (third-party punishment) has a formative influence on societies, yet very few studies of the development of this tendency exist. In most studies where young children have punished, participants have imposed costs on puppets, leaving open the question as to whether young children punish in real third-party situations. Here, five-year-olds were given the opportunity to allocate desirable or unpleasant items to antisocial and neutral adults, who were presented as real and shown on video. Neutral individuals were almost always allocated only desirable items. Antisocial individuals were instead usually allocated unpleasant items, as long as participants were told they would give anonymously. Most participants who were instead told they would give in person did not allocate unpleasant items, although a minority did so. This indicates that the children interpreted the situation as real, and that whereas they genuinely desired to punish antisocial adults, they did not usually dare do so in person. Boys punished more frequently than girls. The willingness of preschoolers to spontaneously engage in third-party punishment, occasionally even risking the social costs of antagonizing an anti-social adult, demonstrates a deep-seated early-developing punitive sentiment in humans.
Website
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Gredeback G, Kaduk K, Bakker M, Gottwald J, Ekberg T, Elsner C, Reid V, Kenward B, 'The neuropsychology of infants' pro-social preferences'
Developmental Cognitive Neuroscience 12 (2015) pp.106-113
ISSN: 1878-9293
Abstract
The current study is the first to investigate neural correlates of infants' detection of pro-and antisocial agents. Differences in ERP component P400 over posterior temporal areas were found during 6-month-olds' observation of helping and hindering agents (Experiment 1), but not during observation of identically moving agents that did not help or hinder (Experiment 2). The results demonstrate that the P400 component indexes activation of infants' memories of previously perceived interactions between social agents. This leads to suggest that similar processes might be involved in infants' processing of pro-and antisocial agents and other social perception processes (encoding gaze direction, goal directed grasping and pointing). (C) 2015 Published by Elsevier Ltd.
Website
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Kenward B, Hellmer K, Soderstrom Winter S, Eriksson M, 'Four-year-olds' strategic allocation of resources: Attempts to elicit reciprocation correlate negatively with spontaneous helping'
COGNITION 136 (2015) pp.1-8
ISSN: 0010-0277
Abstract
Behaviour benefitting others (prosocial behaviour) can be motivated by self-interested strategic concerns as well as by genuine concern for others. Even in very young children such behaviour can be motivated by concern for others, but whether it can be strategically motivated by self-interest is currently less clear. Here, children had to distribute resources in a game in which a rich but not a poor recipient could reciprocate. From four years of age participants strategically favoured the rich recipient, but only when recipients had stated an intention to reciprocate. Six- and eight-year-olds distributed more equally. Children allocating strategically to the rich recipient were less likely to help when an adult needed assistance but was not in a position to immediately reciprocate, demonstrating consistent cross-task individual differences in the extent to which social behaviour is self- versus other-oriented even in early childhood. By four years of age children are capable of strategically allocating resources to others as a tool to advance their own self-interest. (C) 2014 Elsevier B.V. All rights reserved.
Website
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Kenward B, Gredeback G, 'Infants Help a Non-Human Agent'
PLOS ONE 8 (9) (2013)
ISSN: 1932-6203
Abstract Young children can be motivated to help adults by sympathetic concern based upon empathy, but the underlying mechanisms are unknown. One account of empathy-based sympathetic helping in adults states that it arises due to direct-matching mirror-system mechanisms which allow the observer to vicariously experience the situation of the individual in need of help. This mechanism could not account for helping of a geometric-shape agent lacking human-isomorphic bodyparts. Here 17-month-olds observed a ball-shaped non-human agent trying to reach a goal but failing because it was blocked by a barrier. Infants helped the agent by lifting it over the barrier. They performed this action less frequently in a control condition in which the barrier could not be construed as blocking the agent. Direct matching is therefore not required for motivating helping in infants, indicating that at least some of our early helpful tendencies do not depend on human-specific mechanisms. Empathy-based mechanisms that do not require direct-matching provide one plausible basis for the observed helping. A second possibility is that rather than being based on empathy, the observed helping occurred as a result of a goal-contagion process in which the infants were primed with the unfulfilled goal.Website
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Kenward B, 'Over-imitating preschoolers believe unnecessary actions are normative and enforce their performance by a third party'
JOURNAL OF EXPERIMENTAL CHILD PSYCHOLOGY 112 (2) (2012) pp.195-207
ISSN: 0022-0965
Abstract Over-imitation, which is common in children, is the imitation of elements of an action sequence that are clearly unnecessary for reaching the final goal. A variety of cognitive mechanisms have been proposed to explain this phenomenon. Here, 48 3- and 5-year-olds together with a puppet observed an adult demonstrate instrumental tasks that included an unnecessary action. Failure of the puppet to perform the unnecessary action resulted in spontaneous protest by the majority of the children, with some using normative language. Children also protested in comparison tasks in which the puppet violated convention or instrumental rationality. Protest in response to the puppet's omission of unnecessary action occurred even after the puppet's successful achievement of the goal. This observation is not compatible with the hypothesis that the primary cause of over-imitation is that children believe the unnecessary action causes the goal. There are multiple domains that children may believe determine the unnecessary action's normativity, two being social convention and instrumental rationality. Because the demonstration provides no information about which domains are relevant, children are capable of encoding apparently unnecessary action as normative without information as to which domain determines the unnecessary action's normativity. This study demonstrates an early link between two processes of fundamental importance for human culture: faithful imitation and the adherence to and enforcement of norms. (C) 2012 Elsevier Inc. All rights reserved.Website
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Kenward B, Osth T, 'Enactment of third-party punishment by 4-year-olds'
FRONTIERS IN PSYCHOLOGY 3 (2012) pp.1-9
ISSN: 1664-1078
Abstract When prompted, preschoolers advocate punishment for moral transgressions against third parties, but little is known about whether and how they might act out such punishment. In this study, adult demonstrators enacted doll stories in which a perpetrator child doll made an unprovoked attack on a victim child doll, after which an adult doll punished either the perpetrator (consistent punishment) or victim (inconsistent punishment). When asked to help retell the story, given free choice of their own preferred actions for the adult doll, 4-year-olds (N = 32) were influenced by the demonstrated choice of target when selecting a target for punishment or admonishment. This influence was weak following inconsistent punishment, however, because the participants tended to change the story by punishing or admonishing the perpetrator when the demonstrator had punished the victim. Four-year-olds' tendency to select a moral rule violator as a target for punishment is therefore stronger than their tendency to copy the specific actions of adults, which itself is known to be very strong. The evidence suggests that 4-year-olds' enactment of punishment is at least partially based on a belief that antisocial actions deserve to be punished.Website
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Kenward B, Nilsson D, 'Catching of Balls Unexpectedly Thrown or Fired by Cannon'
PERCEPTUAL AND MOTOR SKILLS 113 (1) (2011) pp.171-187
ISSN: 0031-5125 eISSN: 1558-688X
Abstract Although learned actions can be automatically elicited in response to expected stimuli for which they have been prepared, little is known about whether learned actions can be automatically initiated by unexpected stimuli. Responses of unwitting participants to balls unexpectedly thrown by an experimenter (n = 10) or propelled by a hidden ball cannon (n = 22) were recorded by motion capture. Experience of ball catching correlated negatively with hand movement distance, indicating most responses were defensive, but successful catches were made in response to both thrown and fired balls. Although reaction time was faster in response to fired balls, interception was more frequent in response to thrown balls, indicating that movement cues by the thrower facilitated unexpected ball catching. The latency to begin a catching action by the only successful catcher of an unexpectedly fired ball was 296 msec. Given current knowledge of reaction time tasks and latencies of neural substrates of conscious perception and deliberation, it is probable that there was insufficient time available for conscious preparation of catch attempts. Ball catching may represent an example of a learned response which can be rapidly and unconsciously initiated without contextual priming or expectation of the stimulus.Website
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Kenward B, Dahl M, 'Preschoolers Distribute Scarce Resources According to the Moral Valence of Recipients' Previous Actions'
DEVELOPMENTAL PSYCHOLOGY 47 (4) (2011) pp.1054-1064
ISSN: 0012-1649
Abstract Children aged 3 years and 41/2 years old watched a puppet, struggling to achieve goals, who was helped by a 2nd puppet and violently hindered by a 3rd. The children then distributed wooden biscuits between the helper and hinderer. In Experiment 1, when distributing a small odd number of biscuits, 41/2-year-olds (N = 16) almost always gave more to the helper. Children verbally justified their unequal distributions by reference to the helper's prosocial behavior or the hinderer's antisocial behavior. In Experiment 2, when biscuits were more plentiful, 41/2-year-olds (N = 16) usually gave equal numbers to helper and hinderer, indicating that 41/2-year-olds usually preferred not to distribute unequally unless forced to by resource scarcity. Three-year-olds (N = 16 in Experiment 1, N = 20 in Experiment 3) gave more biscuits equally often to the helper and to the hinderer. In many cases, this was because they were confused as to the identities and actions of the puppets, possibly because they were shocked by the hinderer's actions. Two fundamental moral behaviors are therefore demonstrated in young preschoolers: indirect reciprocity of morally valenced acts and a preference for equality when distributing resources, although the cognitive bases for these behaviors remain unclear. These results join other recent studies in demonstrating that the seeds of complex moral understanding and behavior are found early in development.Website
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Kenward B, Karlsson M, Persson J, 'Over-imitation is better explained by norm learning than by distorted causal learning'
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES 278 (1709) (2011) pp.1239-1246
ISSN: 0962-8452
Abstract
In over-imitation, children copy even elements of a goal-directed action sequence that appear unnecessary for achieving the goal. We demonstrate in 4-year olds that the unnecessary action is specifically associated with the goal, not generally associated with the apparatus. The unnecessary action is performed flexibly: 4-year olds usually omit it if it has already been performed by an adult. Most 5-year olds do not verbally report the unnecessary action as necessary when achieving the goal, although most of them report an equivalent but necessary action as necessary. Most 5-year olds explain the necessary action in functional terms, but are unsure as to the function of the unnecessary action. These verbal measures do not support the hypothesis that children over-imitate primarily because they encode unnecessary actions as causing the goal even in causally transparent systems. In a causally transparent system, explanations for over-imitation fitting the results are that children are ignorant of the unnecessary action's purpose, and that they learn a prescriptive norm that it should be carried out. In causally opaque systems, however, for children and for adults, any action performed before achieving the goal is likely to be inferred as causally necessary-this is not over-imitation, but ordinary causal learning.
Website
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Kenward B, Schloegl C, Rutz C, Weir AAS, Bugnyar T, Kacelnik A, 'On the evolutionary and ontogenetic origins of tool-oriented behaviour in New Caledonian crows (Corvus moneduloides)'
BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY 102 (4) (2011) pp.870-877
ISSN: 0024-4066
Abstract New Caledonian crows (Corvus moneduloides) are prolific tool users in captivity and in the wild, and have an inherited predisposition to express tool-oriented behaviours. To further understand the evolution and development of tool use, we compared the development of object manipulation in New Caledonian crows and common ravens (Corvus corax), which do not routinely use tools. We found striking qualitative similarities in the ontogeny of tool-oriented behaviour in New Caledonian crows and food-caching behaviour in ravens. Given that the common ancestor of New Caledonian crows and ravens was almost certainly a caching species, we therefore propose that the basic action patterns for tool use in New Caledonian crows may have their evolutionary origins in caching behaviour. Noncombinatorial object manipulations had similar frequencies in the two species. However, frequencies of object combinations that are precursors to functional behaviour increased in New Caledonian crows and decreased in ravens throughout the study period, ending 6 weeks post-fledging. These quantitative observations are consistent with the hypothesis that New Caledonian crows develop tool-oriented behaviour because of an increased motivation to perform object combinations that facilitate the necessary learning. (c) 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102, 870-877.Website
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Kenward B, '10-month-olds visually anticipate an outcome contingent on their own action'
Infancy 15 (4) (2010) pp.337-361
ISSN: 1525-0008
Abstract It is known that young infants can learn to perform an action that elicits a reinforcer, and that they can visually anticipate a predictable stimulus by looking at its location before it begins. Here, in an investigation of the display of these abilities in tandem, I report that 10-month-olds anticipate a reward stimulus that they generate through their own action: .5 sec before pushing a button to start a video reward, they increase their rate of gaze shifts to the reward location; and during periods of extinction, reward location gaze shifts correlate with bouts of button pushing. The results are consistent with the hypothesis that the infants have an expectation of the outcome of their actions: several alternative hypotheses are ruled out by yoked controls. Such an expectation may, however, be procedural, have minimal content, and is not necessarily sufficient to motivate action.Website
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Lopes M, Melo FS, Kenward B, Santos-Victor J, 'A Computational Model of Social-Learning Mechanisms'
Adaptive Behavior 17 (6) (2009) pp.467-483
ISSN: 1059-7123
Abstract In this article we propose a computational model that describes how observed behavior can influence an observer's own behavior, including the acquisition of new task descriptions. The sources of influence on our model's behavior are: beliefs about the world's possible states and actions causing transitions between them; baseline preferences for certain actions; a variable tendency to infer and share goals in observed behavior; and a variable tendency to act efficiently to reach rewarding states. Acting on these premises, our model is able to replicate key empirical studies of social learning in children and chimpanzees. We demonstrate how a simple artificial system can account for a variety of biological social transfer phenomena, such as goal-inference and over-imitation, by taking into account action constraints and incomplete knowledge about the world dynamics.Website
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Kenward B, Folke S, Holmberg J, Johansson A, Gredeback G, 'Goal Directedness and Decision Making in Infants'
DEVELOPMENTAL PSYCHOLOGY 45 (3) (2009) pp.809-819
ISSN: 0012-1649
Abstract The term goal directed conventionally refers to either of 2 separate process types-motor processes organizing action oriented toward physical targets and decision-making processes that select these targets by integrating desire for and knowledge of action outcomes. Even newborns are goal directed in the first sense, but the status of infants as decision makers (the focus here) is unknown. In this study, 24-month-olds learned to retrieve an object from a box by pressing a button, and then the object's value was increased. After the object's subsequent disappearance. these children were more likely to press the button to try to retrieve the object than were control 24-month-olds who had learned to retrieve the object but for whom the object's value was unchanged. Such sensitivity to outcome value when selecting actions is a hallmark of decision making. However, 14- and 19-month-olds showed no such sensitivity. Possible explanations include that they had not learned the specifics of the action outcome; they had not acquired the necessary desire; or they had acquired both but did not integrate them to make a decision.Website
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Gredeback G, Theuring C, Hauf P, Kenward B, 'The microstructure of infants' gaze as they view adult shifts in overt attention'
INFANCY 13 (5) (2008) pp.533-543
ISSN: 1525-0008
Abstract We presented infants (5, 6, 9, and 12 months old) with movies in which a female model turned toward and fixated 1 of 2 toys placed oil a table. Infants' gaze was measured using a Tobii 1750 eye tracker. Six-, 9-, and 12-month-olds' first gaze shift from the model's face (after the model started turning) was directed to the attended toy. The 5-month-olds performed at random. Following this initial response, 5-, 6, and 9-month-olds performed more gaze shifts to the attended target; 12-month-olds performed at random. Infants at all ages displayed longer looking times to the attended toy. We discuss a number of explanations for 5-month-olds' ability to follow a shift in overt attention by an adult after an initially random response, including the possibility that infants' initial gaze response strengthens the representation of the objects in the peripheral visual field.Website
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Kenward B, Rutz C, Weir AAS, Kacelnik A, 'Development of tool use in New Caledonian crows: inherited action patterns and social influences'
ANIMAL BEHAVIOUR 72 (6) (2006) pp.1329-1343
ISSN: 0003-3472
Abstract New Caledonian crows, Corvus moneduloides, are the most advanced avian tool makers and tool users. We previously reported that captive-bred isolated New Caledonian crows spontaneously use twig tools and cut tools out of Pandanus spp. tree leaves, an activity possibly under cultural influence in the wild. However, what aspects of these behaviours are inherited and how they interact with individual and social experience remained unknown. To examine the interaction between inherited traits, individual learning and social transmission, we observed the ontogeny of twig tool use in hand-reared juveniles. Successful food retrieval was preceded by stereotyped object manipulation action patterns that resembled components of the mature behaviour, demonstrating that tool-oriented behaviours in this species are an evolved specialization. However, there was also an effect of social learning: juveniles that had received demonstrations of twig tool use by their human foster parent showed higher levels of handling and insertion of twigs than did their naive counterparts; a choice experiment showed that they preferred to handle objects that they had seen being manipulated by their human foster parent. Our observations are consistent with the hypothesis that individual learning, cultural transmission and creative problem solving all contribute to the acquisition of the tool-oriented behaviours in the wild, but inherited species-typical action patterns have a greater role than has been recognized. (c) 2006 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.Website
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Kenward B, Kenward RE, Kacelnik A, 'An automatic technique for selective feeding and logging of individual wild squirrels'
Ethology Ecology and Evolution 17 (3) (2005) pp.271-277
ISSN: 0394-9370
Abstract We describe an automated feeding station for squirrels which identifies individuals and logs their feeding times, using passive integrated transponders (PIT tags). The system can provide or deny food to tagged individuals based on identity and/or arbitrary schedules. We test the system with wild grey squirrels Sciurus carolinensis, and report their feeding patterns and their ability to learn to manipulate a joystick to gain access. Possible applications for the system include behavioural or ecological research where the food access of different free-ranging individuals is to be controlled, and the supplementary feeding of red squirrels Sciurus vulgaris.Website
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Kenward B, Weir AAS, Rutz C, Kacelnik A, 'Tool manufacture by naive juvenile crows'
NATURE 433 (121) (2005) pp.121-121
ISSN: 0028-0836
Website
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Kenward B, Wachtmeister CA, Ghirlanda S, Enquist M, Kenward B, Wachtmeister CA, Ghirlanda S, Enquist M, 'Spots and stripes: the evolution of repetition in visual signal form'
JOURNAL OF THEORETICAL BIOLOGY 230 (3) (2004) pp.407-419
ISSN: 0022-5193
Abstract It is common to find spatially repetitive patterns in animal visual signals. The evolution of such patterns is not well explained by existing theories of signal evolution. In this paper, we suggest that the evolution of signals with spatial repetition may be due to specific recognition problems and receiver biases. The logics of our hypotheses are studied in co-evolutionary simulations using artificial neural networks as models of receivers. These simulations yield repetitive visual signals under the following conditions: translations and reflections of the signal, partial obstruction of the signal, a fixed feature in the signal, and lateral inhibition in the receiver. In addition to regular repetitions our simulations sometimes result in other organisations of the signal such as blocky patterns and gradients. Website
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Kenward B, Rutz C, Weir AAS, Chappell J, Kacelnik A, 'Morphology and sexual dimorphism of the New Caledonian Crow Corvus moneduloides, with notes on its behaviour and ecology'
Ibis 146 (4) (2004) pp.652-660
ISSN: 0019-1019
Abstract New Caledonian Crows Corvus moneduloides are known to be extraordinary tool makers and users, but little is known of other aspects of their biology. Here, we report recent field observations of their behaviour and ecology, along with measurements of 19 morphological traits and two flight performance parameters taken from 22 captured Crows. These measurements showed that the Crows were sexually dimorphic in size (the males were larger) but not in shape. We also found that the crows lived in mixed-sex groups, and we observed juvenile-type begging behaviour and feeding by regurgitation, which supports the hypothesis that these may be family groups.Website
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Weir AAS, Kenward B, Chappell J, Kacelnik A, 'Lateralization of tool use in New Caledonian crows (Corvus moneduloides)'
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES 271 (Suppl 5) (2004) pp.S344-S346
ISSN: 0962-8452
Abstract We studied laterality of tool use in 10 captive New Caledonian (NC) crows (Corvus moneduloides). All subjects showed near-exclusive individual laterality, but there was no overall bias in either direction (five were left-lateralized and five were right-lateralized). This is consistent with results in non-human primates, which show strong individual lateralization for tool use (but not for other activities), and also with observations of four wild NC crows by Rutledge & Hunt. jointly, these results contrast with observations that the crows have a population-level bias for manufacturing tools from the left edges of Pandanus sp. leaves, and suggest that the manufacture and use of tools in this species may have different neural underpinnings.Website
Book chapters
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Kacelnik A, Chappell J, Weir AAS, Kenward B, 'Cognitive adaptations for tool-related behaviour in New Caledonian crows' in Wasserman EA, Zentall TR (ed.), Comparative cognition: Experimental explorations of animal intelligence, Oxford University Press (2006)
ISBN: 9780195377804
Website
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Kacelnik A, Chappell J, Weir AAS, Kenward B, 'Tool use and manufacture in birds' in Bekoff M (ed.), Encyclopedia of animal behavior, Greenwood Publishing Group (2004)
ISBN: 978-0313327452
Humans
Kenward, B., Koch, F., Forssman, L., Brehm, J., Tidemann, I., Sundqvist, A., . . . Gredebäck, G. (in press). Saccadic reaction times in infants and adults: spatiotemporal factors, gender, and inter-laboratory variation. Developmental Psychology. [Full open science repository]
Shutts, K., Kenward, B., Falk, H., Ivegran, A., & Fawcett, C. (in press). Early preschool environments and gender: effects of gender pedagogy in Sweden. Journal of Experimental Child Psychology.
Forslund, T., Kenward, B., Granqvist, P., Gredebäck, G., & Brocki, K. C. (2016). Diminished ability to identify facial emotional expressions in children with disorganized attachment representations. Developmental Science, n/a-n/a. doi:10.1111/desc.12465
Gredebäck, G., Kaduk, K., Bakker, M., Gottwald, J., Ekberg, T., Elsner, C., . . . Kenward, B. (2015). The neuropsychology of infants’ pro-social preferences. Developmental Cognitive Neuroscience, 12, 106-113
Kenward, B., Hellmer, K., Söderström Winter, L., & Eriksson, M. (2015). Four-year-olds' strategic allocation of resources: attempts to elicit reciprocation correlate negatively with spontaneous helping. Cognition, 136, 1-8
Kenward, B. & Östh, T. (2015). Five-year-olds punish antisocial adults. Aggressive Behavior, 41, 413-420. [download]
Kenward, B. & Gredebäck, G. (2013). Infants help a non-human agent. PLOS One. [download]
Kenward, B. & Östh, T. (2012). Enactment of third-party punishment by 4-year-olds. Frontiers in Psychology. [download]
Kenward, B. (2012). Over-imitating preschoolers believe unnecessary actions are normative and enforce their performance by a third party. Journal of Experimental Child Psychology. [download]
Kenward, B. & Dahl, M. (2011). Preschoolers distribute resources according to recipients' moral status. Developmental Psychology, 47, 1054-1064. [download]
Kenward, B. & Nilsson, D. (2011). Catching of balls unexpectedly thrown and unexpectedly fired by cannon. Perceptual & Motor Skills, 113, 171-187. [download]
Kenward, B., Karlsson, M. & Persson, J. (2011). Over-imitation is better explained by norm learning than by distorted causal learning. Proceedings of the Royal Society of London B, 278, 1239-1246. [link]
Kenward, B. (2010). 10-month infants visually anticipate the outcome of a learnt action. Infancy, 15, 337-361. [download]
Lopes, M., Melo, F., Kenward, B. & Santos-Victor, J. (2009). A computational model of social-learning mechanisms. Adaptive Behavior, 17, 467-483. [link]
Kenward, B., Folke, S., Holmberg, J., Johansson, A. & Gredebäck, G. (2009). Goal-directedness and decision making in infants. Developmental Psychology, 45, 809-819. [download]
Gredebäck, G., Theuring, C., Hauf, P. & Kenward, B. (2008). The microstructure of infants' gaze during perception of overt attention shifts. Infancy, 13, 533-543.
Other animals
Kenward, B., Schloegl, C., Rutz, C., Weir, A. A. S., Bugnyar, T. & Kacelnik, A. (2011). On the evolutionary and ontogenetic origins of tool-oriented behaviour in New Caledonian crows (Corvus moneduloides).Biological Journal of the Linnean Society, 102, 870-877. [download]
Kenward, B., Rutz, C., Weir, A. A. S. & Kacelnik, A. (2006). Development of tool use in New Caledonian crows: inherited action patterns and social influence. Animal Behaviour, 72, 1329-1343. [download]
Kacelnik, A., Chappell, J., Weir, A. A. S. & Kenward, B. (2006). Cognitive adaptations for tool-related behaviour in New Caledonian crows. In: Comparative cognition: Experimental explorations of animal intelligence (Ed. by Wasserman, E. A. & Zentall, T. R.), pp. 515-528. Oxford: Oxford University Press.
Kenward, B., Weir, A. A. S., Rutz, C. & Kacelnik, A. (2005a). Tool manufacture by naive juvenile crows. Nature, 433, 121-121. [download]
Kenward, B., Kenward, R. E. & Kacelnik, A. (2005b). An automatic technique for selective feeding and logging of individual wild squirrels. Ethology Ecology & Evolution, 17, 271-277.
Kenward, B., Rutz, C., Weir, A. A. S., Chappell, J. & Kacelnik, A. (2004a). Morphology and sexual dimorphism of the New Caledonian crow Corvus moneduloides, with notes on its behaviour and ecology. Ibis, 146, 652-660. [download]
Kenward, B., Wachtmeister, C. A., Ghirlanda, S. & Enquist, M. (2004b). Spots and stripes: the evolution of repetition in visual signal form. Journal of Theoretical Biology, 230, 407-419. [download]
Weir, A. A. S., Kenward, B., Chappell, J. & Kacelnik, A. (2004). Lateralization of tool use in New Caledonian crows (Corvus moneduloides). Proceedings of the Royal Society of London B (Suppl.), 271, S344–S346. [download]
Kacelnik, A., Chappell, J., Weir, A. A. S. & Kenward, B. (2004). Tool use and manufacture in birds. In: Encyclopedia of animal behavior (Ed. by Bekoff, M.), pp. 1067-1069. Westport, CT, US: Greenwood Publishing Group.