Personality consistency in dogs: a meta-analysis

The Other End of the Leash: An Experimental Test to Analyze How Owners Interact with Their Pet Dogs

It has been suggested that the way in which owners interact with their dogs can largely vary and influence the dog-owner bond, but very few objective studies, so far, have addressed how the owner interacts with the dog. The goal of the present study was to record dog owners' interaction styles by means of objective observation and coding. The experiment included eight standardized situations in which owners of pet dogs were asked to perform specific tasks including both positive (i.e. playing, teaching a new task, showing a preference towards an object in a food searching task, greeting after separation) and potentially distressing tasks (i.e. physical restriction during DNA sampling, putting a T-shirt onto the dog, giving basic obedience commands while the dog was distracted). The video recordings were coded off-line using a specifically designed coding scheme including scores for communication, social support, warmth, enthusiasm, and play style, as well as frequency of behaviors like petting, praising, commands, and attention sounds. Exploratory Factor Analysis of the 20 variables measured revealed 3 factors, labeled as Owner Warmth, Owner Social Support, and Owner Control, which can be viewed as analogues to parenting style dimensions. The experimental procedure introduced here represents the first standardized measure of interaction styles of dog owners. The methodology presented here is a useful tool to investigate individual variation in the interaction style of pet dog owners that can be used to explain differences in the dog-human relationship, dogs' behavioral outcomes, and dogs stress coping strategies, all crucial elements both from a theoretical and applied point of view.

Modelling personality, plasticity and predictability in shelter dogs

Behavioural assessments of shelter dogs (Canis lupus familiaris) typically comprise standardized test batteries conducted at one time point, but test batteries have shown inconsistent predictive validity. Longitudinal behavioural assessments offer an alternative. We modelled longitudinal observational data on shelter dog behaviour using the framework of behavioural reaction norms, partitioning variance into personality (i.e. inter-individual differences in behaviour), plasticity (i.e. inter-individual differences in average behaviour) and predictability (i.e. individual differences in residual intra-individual variation). We analysed data on interactions of 3263 dogs (n = 19 281) with unfamiliar people during their first month after arrival at the shelter. Accounting for personality, plasticity (linear and quadratic trends) and predictability improved the predictive accuracy of the analyses compared to models quantifying personality and/or plasticity only. While dogs were, on average, highly sociable with unfamiliar people and sociability increased over days since arrival, group averages were unrepresentative of all dogs and predictions made at the individual level entailed considerable uncertainty. Effects of demographic variables (e.g. age) on personality, plasticity and predictability were observed. Behavioural repeatability was higher one week after arrival compared to arrival day. Our results highlight the value of longitudinal assessments on shelter dogs and identify measures that could improve the predictive validity of behavioural assessments in shelters.

Aggressiveness as a latent personality trait of domestic dogs: Testing local independence and measurement invariance

Studies of animal personality attempt to uncover underlying or “latent” personality traits that explain broad patterns of behaviour, often by applying latent variable statistical models (e.g., factor analysis) to multivariate data sets. Two integral, but infrequently confirmed, assumptions of latent variable models in animal personality are: i) behavioural variables are independent (i.e., uncorrelated) conditional on the latent personality traits they reflect (local independence), and ii) personality traits are associated with behavioural variables in the same way across individuals or groups of individuals (measurement invariance). We tested these assumptions using observations of aggression in four age classes (4–10 months, 10 months–3 years, 3–6 years, over 6 years) of male and female shelter dogs (N = 4,743) in 11 different contexts. A structural equation model supported the hypothesis of two positively correlated personality traits underlying aggression across contexts: aggressiveness towards people and aggressiveness towards dogs (comparative fit index: 0.96; Tucker-Lewis index: 0.95; root mean square error of approximation: 0.03). Aggression across contexts was moderately repeatable (towards people: intraclass correlation coefficient (ICC) = 0.479; towards dogs: ICC = 0.303). However, certain contexts related to aggressiveness towards people (but not dogs) shared significant residual relationships unaccounted for by latent levels of aggressiveness. Furthermore, aggressiveness towards people and dogs in different contexts interacted with sex and age. Thus, sex and age differences in displays of aggression were not simple functions of underlying aggressiveness. Our results illustrate that the robustness of traits in latent variable models must be critically assessed before making conclusions about the effects of, or factors influencing, animal personality. Our findings are of concern because inaccurate “aggressive personality” trait attributions can be costly to dogs, recipients of aggression and society in general.

How do rehomed laboratory beagles behave in everyday situations? Results from an observational test and a survey of new owners

When laboratory dogs are rehomed into private households, they experience an extreme change in their life situation. They leave their familiar, limited environment in the research facility and encounter a multitude of animate and inanimate stimuli in their new home. Although literature reports have described the experiences with rehoming as being mostly positive, scientific observations of the dogs in everyday situations have not been done. Hence, we conducted an observational test with 74 laboratory beagles 6 weeks after adoption in their new homes. This test included standardized tasks and elements; the dogs were observed during specific interactions with their new owners and during a walk. Furthermore, the owners of these 74 and of 71 additional dogs participated in standardized phone interviews 1 and 12 weeks after adoption, during which they answered questions about the dogs’ behavior in everyday situations. In the observational test, the dogs behaved mostly friendly towards humans and dogs, were tolerant during manipulations by the owner and were relaxed during the walk, even in traffic. Eighty percent (of n = 71) of the dogs walked well behaved on the leash without pulling. According to the interviews, the majority of the dogs showed desired, friendly and relaxed behavior, and the survey results reflected the bonding between dog and owner. The analysis of a possible influence of various factors (age, sex, origin, etc.) using mixed regression models confirmed the results from two previous behavior tests and interviews. Specifically, dogs that had been bred in the research facility scored significantly better than dogs that the research facility had purchased from commercial laboratory dog breeders (p = 0.0113). The results of this study demonstrate a successful adaptation of the rehomed beagles to their new life situation.

An evidence-based decision assistance model for predicting training outcome in juvenile guide dogs

Working dog organisations, such as Guide Dogs, need to regularly assess the behaviour of the dogs they train. In this study we developed a questionnaire-style behaviour assessment completed by training supervisors of juvenile guide dogs aged 5, 8 and 12 months old (n = 1,401), and evaluated aspects of its reliability and validity. Specifically, internal reliability, temporal consistency, construct validity, predictive criterion validity (comparing against later training outcome) and concurrent criterion validity (comparing against a standardised behaviour test) were evaluated. Thirty-nine questions were sourced either from previously published literature or created to meet requirements identified via Guide Dogs staff surveys and staff feedback. Internal reliability analyses revealed seven reliable and interpretable trait scales named according to the questions within them as: Adaptability; Body Sensitivity; Distractibility; Excitability; General Anxiety; Trainability and Stair Anxiety. Intra-individual temporal consistency of the scale scores between 5–8, 8–12 and 5–12 months was high. All scales excepting Body Sensitivity showed some degree of concurrent criterion validity. Predictive criterion validity was supported for all seven scales, since associations were found with training outcome, at at-least one age. Thresholds of z-scores on the scales were identified that were able to distinguish later training outcome by identifying 8.4% of all dogs withdrawn for behaviour and 8.5% of all qualified dogs, with 84% and 85% specificity. The questionnaire assessment was reliable and could detect traits that are consistent within individuals over time, despite juvenile dogs undergoing development during the study period. By applying thresholds to scores produced from the questionnaire this assessment could prove to be a highly valuable decision-making tool for Guide Dogs. This is the first questionnaire-style assessment of juvenile dogs that has shown value in predicting the training outcome of individual working dogs.

Development of the "Highly Sensitive Dog" questionnaire to evaluate the personality dimension "Sensory Processing Sensitivity" in dogs

In humans, the personality dimension 'sensory processing sensitivity (SPS)', also referred to as "high sensitivity", involves deeper processing of sensory information, which can be associated with physiological and behavioral overarousal. However, it has not been studied up to now whether this dimension also exists in other species. SPS can influence how people perceive the environment and how this affects them, thus a similar dimension in animals would be highly relevant with respect to animal welfare. We therefore explored whether SPS translates to dogs, one of the primary model species in personality research. A 32-item questionnaire to assess the "highly sensitive dog score" (HSD-s) was developed based on the "highly sensitive person" (HSP) questionnaire. A large-scale, international online survey was conducted, including the HSD questionnaire, as well as questions on fearfulness, neuroticism, "demographic" (e.g. dog sex, age, weight; age at adoption, etc.) and "human" factors (e.g. owner age, sex, profession, communication style, etc.), and the HSP questionnaire. Data were analyzed using linear mixed effect models with forward stepwise selection to test prediction of HSD-s by the above-mentioned factors, with country of residence and dog breed treated as random effects. A total of 3647 questionnaires were fully completed. HSD-, fearfulness, neuroticism and HSP-scores showed good internal consistencies, and HSD-s only moderately correlated with fearfulness and neuroticism scores, paralleling previous findings in humans. Intra- (N = 447) and inter-rater (N = 120) reliabilities were good. Demographic and human factors, including HSP score, explained only a small amount of the variance of HSD-s. A PCA analysis identified three subtraits of SPS, comparable to human findings. Overall, the measured personality dimension in dogs showed good internal consistency, partial independence from fearfulness and neuroticism, and good intra- and inter-rater reliability, indicating good construct validity of the HSD questionnaire. Human and demographic factors only marginally affected the HSD-s suggesting that, as hypothesized for human SPS, a genetic basis may underlie this dimension within the dog species.

Breed, sex, and litter effects in 2-month old puppies' behaviour in a standardised open-field test

A considerable number of studies have reported differences among dog breeds with respect to their genetic profile, cognitive abilities or personality traits. Each dog breed is normally treated as a homogeneous group, however, researchers have recently questioned whether the behavioural profile of modern breeds still reflects their historical function or if the intense divergent selective pressures and geographical barriers have created a more fragmented picture. The majority of studies attempting to assess and compare modern breeds’ personality focused on the evaluation of adult dogs where the potential effects of environmental/human factors on the dogs’ behaviour are hard to discern from their genetic heritage. In the following study, we aimed at investigating between- and within-breed differences in the personality of two-months-old puppies by direct behavioural observation of 377 puppies from 12 breeds. Results showed that there was no effect of sex, however both breed and litter, significantly affected all personality traits. Breed on average explained 10% of the variance, whereas the effect of litter was noticeably higher, explaining on average 23% of the variance. Taken together, our results suggest that breed does have some influence on personality traits, but they also highlight the importance of taking litter effects into account.

Functional MRI in Awake Dogs Predicts Suitability for Assistance Work

The overall goal of this work was to measure the efficacy of fMRI for predicting whether a dog would be a successful service dog. The training and imaging were performed in 49 dogs entering service training at 17–21 months of age. 33 dogs completed service training and were matched with a person, while 10 were released for behavioral reasons (4 were selected as breeders and 2 were released for medical reasons.) After 2 months of training, fMRI responses were measured while each dog observed hand signals indicating either reward or no reward and given by both a familiar handler and a stranger. Using anatomically defined ROIs in the caudate, amygdala, and visual cortex, we developed a classifier based on the dogs’ subsequent training outcomes. The classifier had a positive predictive value of 94% and a negative predictive value of 67%. The area under the ROC curve was 0.91 (0.80 with 4-fold cross-validation, P = 0.01), indicating a significant predictive capability. The magnitude of response in the caudate was positively correlated with a successful outcome, while the response in the amygdala depended on the interaction with the visual cortex during the stranger condition and was negatively correlated with outcome (higher being associated with failure). These results suggest that, as indexed by caudate activity, successful service dogs generalize associations to hand signals regardless who gives them but without excessive arousal as measured in the amygdala.

Using network analysis to study behavioural phenotypes: an example using domestic dogs

Phenotypic integration describes the complex interrelationships between organismal traits, traditionally focusing on morphology. Recently, research has sought to represent behavioural phenotypes as composed of quasi-independent latent traits. Concurrently, psychologists have opposed latent variable interpretations of human behaviour, proposing instead a network perspective envisaging interrelationships between behaviours as emerging from causal dependencies. Network analysis could also be applied to understand integrated behavioural phenotypes in animals. Here, we assimilate this cross-disciplinary progression of ideas by demonstrating the use of network analysis on survey data collected on behavioural and motivational characteristics of police patrol and detection dogs (Canis lupus familiaris). Networks of conditional independence relationships illustrated a number of functional connections between descriptors, which varied between dog types. The most central descriptors denoted desirable characteristics in both patrol and detection dog networks, with 'Playful' being widely correlated and possessing mediating relationships between descriptors. Bootstrap analyses revealed the stability of network results. We discuss the results in relation to previous research on dog personality, and benefits of using network analysis to study behavioural phenotypes. We conclude that a network perspective offers widespread opportunities for advancing the understanding of phenotypic integration in animal behaviour.

Why Did the Dog Walk Into the MRI?

Because he was trained to. The domestic dog’s accessibility, social intelligence, and evolutionary history with humans have led to increasing interest in canine cognition. Despite a growing body of data on canine behavior and cognitive skills, relatively few advances have been made in understanding canine brain function. Practical and ethical concerns had limited the use of the invasive brain-imaging techniques typically used with primate and rodent models. However, the demonstration that dogs can be trained to cooperatively participate in fMRI studies has opened up a wealth of new data about canine brain function. Many of these studies have investigated the dog’s preternatural social intelligence, focusing on neural pathways associated with different types of reward, including social reward, and face and vocal processing. These studies have implications for our understanding of canine brain function, and potentially, because of dogs’ close relations with humans, for models of human development and pathology.

Using network analysis to study behavioural phenotypes: an example using domestic dogs

Phenotypic integration describes the complex interrelationships between organismal traits, traditionally focusing on morphology. Recently, research has sought to represent behavioural phenotypes as composed of quasi-independent latent traits. Concurrently, psychologists have opposed latent variable interpretations of human behaviour, proposing instead a network perspective envisaging interrelationships between behaviours as emerging from causal dependencies. Network analysis could also be applied to understand integrated behavioural phenotypes in animals. Here, we assimilate this cross-disciplinary progression of ideas by demonstrating the use of network analysis on survey data collected on behavioural and motivational characteristics of police patrol and detection dogs (Canis lupus familiaris). Networks of conditional independence relationships illustrated a number of functional connections between descriptors, which varied between dog types. The most central descriptors denoted desirable characteristics in both patrol and detection dog networks, with 'Playful' being widely correlated and possessing mediating relationships between descriptors. Bootstrap analyses revealed the stability of network results. We discuss the results in relation to previous research on dog personality, and benefits of using network analysis to study behavioural phenotypes. We conclude that a network perspective offers widespread opportunities for advancing the understanding of phenotypic integration in animal behaviour.

A systematic review and meta-analysis of salivary cortisol measurement in domestic canines

Salivary cortisol is widely used as an indicator of stress and welfare in canine research. However, much remains unclear about the basic features of this hormone marker in domestic dogs. This systematic review and meta-analysis aimed to determine a reference range for cortisol concentration in the saliva of dogs and examine how canine characteristics, environmental effects and experimental considerations relate to salivary cortisol concentrations. A systematic review of literature databases and conference proceedings from 1992 to 2012 identified 61 peer-reviewed studies using domestic dog salivary cortisol. Researchers were contacted via email, and 31 raw data sets representing a total of 5,153 samples from 1,205 dogs were shared. Meta-analysis provided a cortisol concentration range of 0 to 33.79 μg/dL (mean 0.45 μg/dL, SEM 0.13). Significant effects (P < 0.05) were found for sex and neuter status, age, regular living environment, time in environment before testing, testing environment, owner presence during testing, and collection media. Significant effects were not found for dog breed, body weight, dog type, coat color, assay type, exercise, eating, or use of salivary stimulant. Care should be taken when using cortisol studies for dogs at a group or population level as there is a large amount of intraindividual and interindividual variability and external variables could influence salivary cortisol concentration. This analysis highlights the importance of carefully controlling experimental design to compare samples within and between individual dogs, as well as establishing and using best practices for saliva collection. Caution should be exercised in comparing different studies, as the results could be the reflection of a plethora of factors.

Current Trends in Canine Problem-Solving and Cognition

Dogs have occupied a central place in modern comparative cognition, partly because of their specific past and present relationship with humans. Over the years, we have gained insights about the functioning of the dog’s mind, which has helped us to understand how dogs’ problem-solving abilities differ from those present in related species such as the wolf. Novel methodologies are also emerging that allow for the study of neural and genetic mechanisms that control mental functions. By providing an overview from an ethological perspective, we call for greater integration of the field and a better understanding of natural dog behavior as a way to generate scientific hypotheses.

Individual and group level trajectories of behavioural development in Border collies

In order to assess dogs' personality changes during ontogeny, a cohort of 69 Border collies was followed up from six to 18-24 months. When the dogs were 6, 12, and 18-24 months old, their owners repeatedly filled in a dog personality questionnaire (DPQ), which yielded five personality factors divided into fifteen facets. All five DPQ factors were highly correlated between the three age classes, indicating that the dogs' personality remained consistent relative to other individuals. Nonetheless, at the group level significant changes with age were found for four of the five DPQ factors. Fearfulness, Aggression towards People, Responsiveness to Training and Aggression towards Animals increased with age; only Activity/Excitability did not change significantly over time. These changes in DPQ factor scores occurred mainly between the ages of 6 and 12 months, although some facets changed beyond this age. No sex differences were found for any of the tested factors or facets, suggesting that individual variation in personality was greater than male/female differences. There were significant litter effects for the factors Fearfulness, Aggression towards People and Activity/Excitability, indicating either a strong genetic basis for these traits or a high influence of the shared early environment. To conclude, from the age of six months, consistency in personality relative to other individuals can be observed in Border collies. However, at the group level, increases in fearful and aggressive behaviours occur up to 12 months and for some traits up to two years, highlighting the need for early interventions. Follow-up studies are needed to assess trajectories of personality development prior to six months and after two years, and to include a wider variety of breeds.

Does Subjective Rating Reflect Behavioural Coding? Personality in 2 Month-Old Dog Puppies: An Open-Field Test and Adjective-Based Questionnaire

A number of studies have recently investigated personality traits in non-human species, with the dog gaining popularity as a subject species for research in this area. Recent research has shown the consistency of personality traits across both context and time for adult dogs, both when using questionnaire based methods of investigation and behavioural analyses of the dogs' behaviour. However, only a few studies have assessed the correspondence between these two methods, with results varying considerably across studies. Furthermore, most studies have focused on adult dogs, despite the fact that an understanding of personality traits in young puppies may be important for research focusing on the genetic basis of personality traits. In the current study, we sought to evaluate the correspondence between a questionnaire based method and the in depth analyses of the behaviour of 2-month old puppies in an open-field test in which a number of both social and non-social stimuli were presented to the subjects. We further evaluated consistency of traits over time by re-testing a subset of puppies. The correspondence between methods was high and test- retest consistency (for the main trait) was also good using both evaluation methods. Results showed clear factors referring to the two main personality traits 'extroversion,' (i.e. the enthusiastic, exuberant approach to the stimuli) and 'neuroticism,' (i.e. the more cautious and fearful approach to the stimuli), potentially similar to the shyness-boldness dimension found in previous studies. Furthermore, both methods identified an 'amicability' dimension, expressing the positive interactions the pups directed at the humans stranger, and a 'reservedness' dimension which identified pups who largely chose not to interact with the stimuli, and were defined as quiet and not nosey in the questionnaire.

Inhibitory Control, but Not Prolonged Object-Related Experience Appears to Affect Physical Problem-Solving Performance of Pet Dogs

Human infants develop an understanding of their physical environment through playful interactions with objects. Similar processes may influence also the performance of non-human animals in physical problem-solving tasks, but to date there is little empirical data to evaluate this hypothesis. In addition or alternatively to prior experiences, inhibitory control has been suggested as a factor underlying the considerable individual differences in performance reported for many species. Here we report a study in which we manipulated the extent of object-related experience for a cohort of dogs (Canis familiaris) of the breed Border Collie over a period of 18 months, and assessed their level of inhibitory control, prior to testing them in a series of four physical problem-solving tasks. We found no evidence that differences in object-related experience explain variability in performance in these tasks. It thus appears that dogs do not transfer knowledge about physical rules from one physical problem-solving task to another, but rather approach each task as a novel problem. Our results, however, suggest that individual performance in these tasks is influenced in a complex way by the subject’s level of inhibitory control. Depending on the task, inhibitory control had a positive or a negative effect on performance and different aspects of inhibitory control turned out to be the best predictors of individual performance in the different tasks. Therefore, studying the interplay between inhibitory control and problem-solving performance will make an important contribution to our understanding of individual and species differences in physical problem-solving performance.

Early Life Experiences and Exercise Associate with Canine Anxieties

Personality and anxiety disorders across species are affected by genetic and environmental factors. Shyness-boldness personality continuum exists across species, including the domestic dog, with a large within- and across-breed variation. Domestic dogs are also diagnosed for several anxiety-related behavioral conditions, such as generalized anxiety disorders, phobias, and separation anxiety. Genetic and environmental factors contributing to personality and anxiety are largely unknown. We collected questionnaire data from a Finnish family dog population (N = 3264) in order to study the associating environmental factors for canine fearfulness, noise sensitivity, and separation anxiety. Early life experiences and exercise were found to associate with anxiety prevalence. We found that fearful dogs had less socialization experiences (p = 0.002) and lower quality of maternal care (p < 0.0001) during puppyhood. Surprisingly, the largest environmental factor associating with noise sensitivity (p < 0.0001) and separation anxiety (p = 0.007) was the amount of daily exercise; dogs with noise sensitivity and separation anxiety had less daily exercise. Our findings suggest that dogs share many of the same environmental factors that contribute to anxiety in other species as well, such as humans and rodents. Our study highlights the importance of early life experiences, especially the quality of maternal care and daily exercise for the welfare and management of the dogs, and reveals important confounding factors to be considered in the genetic characterization of canine anxiety.

The importance of genotype-by-age interactions for the development of repeatable behavior and correlated behaviors over lifetime

Behaviors are highly plastic and one aspect of this plasticity is behavioral changes over age. The presence of age-related plasticity in behavior opens up the possibility of between-individual variation in age-related plasticity (Individual-Age interaction, IxA) and genotype-age interaction (GxA). We outline the available approaches for quantifying GxA. We underline that knowledge of GxA for behaviors is an important step in reaching and understanding of the evolution of plasticity in behavior over lifetime. In particular, the heritability (repeatability) and/or the rank order of behavior across individuals are predicted to change across ages in presence of GxA. We draw on the theory of reaction norms to illustrate that GxA, when present, is likely to lead to developmental changes in the magnitude and possibly sign of the genetic correlation between behaviors (behavioral syndrome). We present an overview of the literature on changes in the ranking of individuals’ behavior across ages, and in the correlation between behaviors. Although all studies were carried out on the phenotypic level, they overall suggest clear scope for increased study of GxA as a process explaining age-related plasticity in behaviors. Lastly, we throughout emphasize that many of the approaches and underlying theory of GxA is applicable to the study of IxA, which is informative as it presents the upper limit of GxA, but is also a more attainable target of study in many systems. Empirical work aimed at understanding IxA and GxA in behavior is needed in order to understand whether patterns predicted by theory on plasticity indeed occur for age-related plasticity of behavior.

A comparison of rating and coding behavioural traits in dogs

The aim of the present study was to examine the links between independent rating and coding approaches to assessing activity-impulsivity and inattention in dogs. Fifty-six adult Belgian shepherd dogs were videotaped performing in behavioural tests. Seventeen behavioural variables were measured by coders (video coding). Raters watched the same videotapes and then rated the activity-impulsivity and inattention of each dog (video rating). Owners filled out the Dog ADHS-RS questionnaire measuring activity-impulsivity and inattention. Video rating of activity-impulsivity correlated with the scale scores of the owner, but video codings did not. The results suggest that the owner ratings and video ratings are tapping the same constructs, but behavioural variables assessed in the present study were not appropriate for mirroring the owners' assessments. The findings suggest that if consistent individual differences in broad behavioural traits are the primary focus of analyses, then ratings seem to capture information not easily captured in coding approaches designed to assess the same constructs.

The advent of canine performance science: offering a sustainable future for working dogs

Working and sporting dogs provide an essential contribution to many industries worldwide. The common development, maintenance and disposal of working and sporting dogs can be considered in the same way as other animal production systems. The process of 'production' involves genetic selection, puppy rearing, recruitment and assessment, training, housing and handling, handler education, health and working life end-point management. At present, inefficiencies throughout the production process result in a high failure rate of dogs attaining operational status. This level of wastage would be condemned in other animal production industries for economic reasons and has significant implications for dog welfare, as well as public perceptions of dog-based industries. Standards of acceptable animal use are changing and some historically common uses of animals are no longer publicly acceptable, especially where harm is caused for purposes deemed trivial, or where alternatives exist. Public scrutiny of animal use appears likely to increase and extend to all roles of animals, including working and sporting dogs. Production system processes therefore need to be transparent, traceable and ethically acceptable for animal use to be sustainable into the future. Evidence-based approaches already inform best practice in fields as diverse as agriculture and human athletic performance. This article introduces the nascent discipline of canine performance science, which aims to facilitate optimal product quality and production efficiency, while also assuring evidence-based increments in dog welfare through a process of research and development. Our thesis is that the model of canine performance science offers an objective, transparent and traceable opportunity for industry development in line with community expectations and underpins a sustainable future for working dogs. This article is part of a Special Issue entitled: Canine Behavior.

Which personality dimensions do puppy tests measure? A systematic procedure for categorizing behavioral assays

With the recent increase in interest in personality in dogs, behavioral assays of their behavior have proliferated. There has been particularly strong interest in predicting adult behavior from puppy tests. As a result, researchers and practitioners seeking to measure personality in puppies are faced with a bewildering array of options and no clear guide as to what behavioral assays have been developed or which personality dimensions those assays measure effectively. To address this issue, we used an 'expert-categorization' procedure-a standardized method often used in the course of meta-analyses-to identify the subset of those assays consensually judged to measure major personality dimensions effectively. We used this procedure to identify all relevant puppy tests and to categorize them in terms of their ability to measure nine personality dimensions identified in previous research (activity, aggressiveness, boldness/self-assuredness, exploration, fearfulness/nervousness, reactivity, sociability, submissiveness, trainability/responsiveness). Specifically, we identified 264 assay subtests, derived from 47 studies, which were subjected to a standardized categorization procedure undertaken independently by six expert judges. These procedures yielded a set of behavioral tests judged to measure the nine dimensions effectively and also demonstrated a widely applicable method for developing and evaluating behavioral test batteries. This article is part of a Special Issue entitled: Canine Behavior.

Do you see what I see? Can non-experts with minimal training reproduce expert ratings in behavioral assessments of working dogs?

Working-dog organizations often use behavioral ratings by experts to evaluate a dog's likelihood of success. However, these experts are frequently under severe time constraints. One way to alleviate the pressure on limited organizational resources would be to use non-experts to assess dog behavior. Here, in populations of military working dogs (Study 1) and explosive-detection dogs (Study 2), we evaluated the reliability and validity of behavioral ratings assessed by minimally trained non-experts from videotapes. Analyses yielded evidence for generally good levels of inter-observer reliability and criterion validity (indexed by convergence between the non-expert ratings and ratings made previously by experts). We found some variation across items in Study 2 such that reliability and validity was significantly lower for three out of the 18 items, and one item had reliability and validity estimates that were impacted heavily by the behavioral test environment. There were no differences in reliability and validity based on the age of the dog. Overall the results suggest that ratings made by minimally trained non-experts for most items can serve as a viable alternative to expert ratings freeing limited resources of highly trained staff. This article is part of a Special Issue entitled: Canine Behavior.

The predictive value of early behavioural assessments in pet dogs--a longitudinal study from neonates to adults

Studies on behavioural development in domestic dogs are of relevance for matching puppies with the right families, identifying predispositions for behavioural problems at an early stage, and predicting suitability for service dog work, police or military service. The literature is, however, inconsistent regarding the predictive value of tests performed during the socialisation period. Additionally, some practitioners use tests with neonates to complement later assessments for selecting puppies as working dogs, but these have not been validated. We here present longitudinal data on a cohort of Border collies, followed up from neonate age until adulthood. A neonate test was conducted with 99 Border collie puppies aged 2–10 days to assess activity, vocalisations when isolated and sucking force. At the age of 40–50 days, 134 puppies (including 93 tested as neonates) were tested in a puppy test at their breeders' homes. All dogs were adopted as pet dogs and 50 of them participated in a behavioural test at the age of 1.5 to 2 years with their owners. Linear mixed models found little correspondence between individuals' behaviour in the neonate, puppy and adult test. Exploratory activity was the only behaviour that was significantly correlated between the puppy and the adult test. We conclude that the predictive validity of early tests for predicting specific behavioural traits in adult pet dogs is limited.

Impulsive for life? The nature of long-term impulsivity in domestic dogs

Individual differences in impulsivity occur at a cognitive and/or behavioural level and are associated with differing life outcomes. However, there is a lack of empirical evidence to support the long-term stability of these characteristics in non-human animals. This study reports on the stability of convergent measures of impulsivity in domestic dogs assessed more than 6 years apart. Measures were (1) owner assessment by means of a questionnaire, the validated 'Dog Impulsivity Assessment Scale' (DIAS) and (2) dogs' performance in a delayed reward choice test. Dogs had 15-min free access to two food dispensers, one dispensing a piece of food immediately, the other dispensing three pieces after a delay, which increased by 1 s every other time the dogs sampled it. Maximum delay reached in this task reflects decision-making, or cognitive impulsivity, whereas the rate of extra presses on the delayed reward device during the delay can be considered as a measure of motor or behavioural impulsivity. DIAS scores were strongly and significantly correlated across years. The maximum delay reached in the behaviour test was also highly stable, whereas paw-pressing rate was uncorrelated between the years. These results demonstrate that cognitive but not motor impulsivity is highly consistent over time in dogs.