The idea of animals possessing personalities was once dismissed by the scientific community, but has since gained traction with evidence for potential application to improve captive animal management and welfare. Although domestic cats are popular companion animals, research has tended to overlook the value of personality assessment for management and care of pet cats. The aim of this study was to investigate personality in a large sample of pet cats with a view to understanding practical implications for pet cats in the home. Personality of 2,802 pet cats, from South Australia and New Zealand, was rated by their owners utilising a survey measuring 52 personality traits. Five reliable personality factors were found using principal axis factor analysis: Neuroticism, Extraversion, Dominance, Impulsiveness and Agreeableness. Implications for the ‘Feline Five’ are discussed in relation to their potential application to improving the management and welfare of pet cats. Highly Impulsive cats for example, may be reacting to something stressful in their environment, whereas cats with low Agreeableness scores, showing irritability may indicate underlying pain or illness. Thus, the need for a systematic and holistic approach to personality that includes both the individual pet cat and its environment is recommended, and opens the door to future interdisciplinary intervention.

Funding: The project (PR) received funding from the South Australian Dog and Cat Management Board ( http://www.dogandcatboard.com.au/ ). The project (PR) was also funded by the University of South Australia’s Discovery Circle Initiative ( http://www.discoverycircle.org.au ) which receives external funding from the Adelaide and Mt Lofty Ranges Natural Resources Management Board; Department of Environment, Water and Natural Resources; City of Marion; and City of Salisbury.

Copyright: © 2017 Litchfield et al. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Introduction

Domestic cats have been companion animals for thousands of years [1], and are popular pets in Australia, New Zealand, Europe, North America and elsewhere [2]. Yet, we know little about typical pet cat behaviour, with most behavioural studies conducted in laboratories, shelters or on free-ranging feral cat colonies [3]. This gap in knowledge is problematic since the typical environment for domestic cats is arguably the home, with tens of millions of pet cats, some kept exclusively indoors [3]. Cat owners, veterinarians, animal behaviourists and scientists often focus on the behavioural problems of stressed cats rather than on the behaviour of psychologically healthy cats and their inter- and intra-species interactions. Development of an accurate standardised ethogram (inventory of species-specific behaviours) for pet cats would facilitate creation of standards for optimal housing and welfare, like the Five Freedoms for captive animals [4].

It is possible for cats living in a multi-cat household to time-share favourite places [5], choose to spend time in close proximity with another cat [6], or play with a dog companion, with both species able to interpret each other’s behaviour correctly if they have been together from a young age [7]. Cats are more sociable than many people realise [8], and a basic understanding of cat behaviour [9] and signals (e.g. vocalisations) can allow owners to assess social stress in their cats [8], with veterinarians and other professionals able to provide this information to kitten or cat owners [10]. Understanding social interactions between cats (in the same household or neighbourhood) and between cats and their owners is important since many urban pet cats may be suffering chronic stress, as a result of lack of control over their environment [8]. A better understanding of cat personality by means of assessment could help owners improve conditions for their cats at home, thereby supporting the optimal wellbeing of their feline companions.

Personality in animals Personality refers to consistent individual differences in behavioural patterns [11] and is sometimes labelled as temperament [12] or behavioural syndromes [13], although a standardised term, personality, should be applicable in all cases. Personality in animals has been investigated by scientists in various fields [14], with a bias towards species considered most useful to humans, such as primates for their genetic closeness [15] and canids for their working ability [16]. However, as popular pets, an understanding of domestic cat personality could improve domestic cat welfare, by allowing carers to tailor management strategies to suit individual cats, since animal personality has been shown to influence behaviour [17], health outcomes [18], wellbeing [19], and welfare [20]. In Australia, research has tended to focus on behavioural problems related to owned and un-owned/stray cats [21, 22] rather than on the potential value of personality assessment. In Australia, almost 53,000 cats were received by RSPCA shelters in 2014–2015, with about a third of these cats eventually euthanized [23], and in the United States, an estimated 3.4 million cats enter animal shelters annually, with about 41% of these euthanized [24]. Personality assessment may increase compatibility of cat-owner placements through shelter adoption [2], with the understanding that personality of owners also influences cat behaviour [25] and therefore ideally both personality of prospective owner and cat would be assessed for compatibility [26]. For example, people scoring high on Neuroticism may have fewer and less complex interactions with their cats [25]. Cat owners through use of informed management practices, such as appropriate housing, enrichment, grouping, health and wellbeing strategies related to individual cat personalities may enhance the quality of life of their cats.

Measures of cat personality Early cat personality studies relied on systematic observation of cat behaviour and coding methods, which involves generating an ethogram, and then systematically recording frequency or duration of behavioural categories [16, 27, 28], such as a cat’s responses to presentations of novel objects [29, 30] or unfamiliar persons [2, 31, 32]. Though coding was considered to be objective [14], the subjective rating of comprehensive personality traits by people (usually carers) who know the animals well (the rating method), is now used more frequently [8, 25], and is considered a more reliable, practical and time-efficient approach [33]. Following the generation of a comprehensive list of species-relevant behavioural traits [34], rating usually occurs along a Likert scale to indicate the level of trait expression generally demonstrated by the animals [16]. Data are then typically reduced into a consolidated number of personality dimensions or factors, each comprising reflective personality traits using dimension reduction statistics, such as principal components analysis [28, 35].

Research on personality in domestic cats Investigations of cat personality have focused on either: the continuum of one personality dimension, such as dominance-warmth [36], which may allow for a more thorough investigation; or more commonly on multiple dimensions at once [37, 38], typically adapting the commonly used approach in human personality research, the Five-Factor Model (FFM), sometimes known as the Big Five [37, 39]. The FFM model is comprised of the dimensions Neuroticism, Extraversion, Openness to Experience, Conscientiousness and Agreeableness. The theory behind the model suggests an individual’s personality is determined by where they exist along each factor continuum [34] (see Fig 1 adapted from [40]). PPT PowerPoint slide

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larger image TIFF original image Download: Fig 1. The FFM continuum and an example of how an individual's personality might be scored (based on terminology from John & Srivastava, 1999). https://doi.org/10.1371/journal.pone.0183455.g001 Domestic cat personality research has tended to explore development of behaviour directed at humans, socialisation, and the shy-bold continuum of cat personality in relation to humans [30–32, 35, 41]. Individual differences exist in the extent to which cats accept the approach of, or handling by an unfamiliar person [32, 35], which is potentially influenced by the friendliness of a cat’s sire as well as socialisation effects [30, 41]. The shy-bold continuum in relation to inter-cat social behaviour has also been investigated [42], with bolder cats more vulnerable to feline immunodeficiency virus, which has potential health implications for pet cats in the home.

Methodological challenges facing studies of cat personality A multidimensional examination of personality in cats [43] served as a foundational study design, which used subjective trait ratings in a personality survey designed for rhesus monkeys (Macaca mulatta), which was modified following behavioural observation of cats in a laboratory over three months. Despite the limited generalizability of the sample (n = 14, female only, and laboratory environment), inter-cat social behaviour was observed and recorded, allowing successful validation of initial subjective assessments. Some of the methodological limitations or weaknesses of domestic cat personality studies conducted to date include: (1) lack of information on length of familiarity between cats and the people rating them [41]; (2) lack of acknowledgement of possible influence that researchers may have on cat behaviour when observing them in their homes [25]; (3) small sample sizes, such as 14 cats [43] or 40 cats [25, 41], with 440 cats representing the largest sample rated by their owners following recruitment over the Internet [38]; and (4) insufficient reporting of reliability assessments with inter-rater/observer reliability coefficients the most commonly reported values, conveying varying levels of agreement between raters/observers in their impressions of cat personality trait expression [25, 37, 41, 43]. Another problem concerns the inconsistent nomenclature or labelling used for cat personality trait and factors. The dimension reduction technique principal components analysis (PCA), coupled with exploratory factor analysis (EFA), is recommended to analyse statistical correlations among personality traits that cluster together creating overall components [34]. For example, the highest factor loadings on traits such as anxious, insecure, tense, and so on, have resulted in labelling the factor as Neuroticism [37]. The labelling of a factor as Feeding in one study [25], with its behavioural inclination makes its applicability to personality questionable [16]. Moreover, a lack of standardised personality factor labels and their corresponding traits is obstructing replication studies and consequently progress in cat personality research [38]. Thus, a standardised use of terms guided by previous research [44], such as the well-established human FFM nomenclature is recommended. Following identification of personality factors, researchers should assess consistency of these factors across situations [45], with evaluation of validity to determine whether the assessment tool actually measures personality [46]. For example, the two-step process [25, 43] allows subjective ratings to be converged with coded behaviours, in order to identify and validate personality factors with some respectable coefficients (e.g. > .70), thereby strengthening accuracy of findings. Content validity was likely compromised in one application of human personality traits to cats [38] since not all domains of cat personality may have been captured in their use of only the human FFM.

Application of personality assessment for improved cat management and welfare Previous research on captive wild felids has led to suggestions of potential application of personality assessment to captive animal management and welfare, such as socially compatible enclosure groupings created for Scottish wildcats (Felis silvestris) [19] and provision of ample hiding places for highly tense-fearful cheetahs (Acinonyx jubatus) [20]. These applications may also be relevant to domestic pet cat management, particularly for grouping of compatible cats in multi-cat households, or providing neurotic pet cats with additional hiding places. To facilitate the use of personality assessment as a means of improving pet cat management and welfare, the methodological challenges facing research in this area, including small sample sizes, must be addressed.