Slow Blink Eye Closure in Shelter Cats Is Related to Quicker Adoption
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animals Article Slow Blink Eye Closure in Shelter Cats Is Related to Quicker Adoption Tasmin Humphrey 1,* , Faye Stringer 1, Leanne Proops 2 and Karen McComb 1,* 1 Mammal Communication and Cognition Research Group, School of Psychology, University of Sussex, Brighton BN1 9QH, UK; [email protected] 2 Centre for Comparative and Evolutionary Psychology, Department of Psychology, University of Portsmouth, Portsmouth PO1 2DY, UK; [email protected] * Correspondence: [email protected] (T.H.); [email protected] (K.M.) Received: 27 October 2020; Accepted: 23 November 2020; Published: 30 November 2020 Simple Summary: Slow blinking is a type of interaction between humans and cats that involves a sequence of prolonged eye narrowing movements being given by both parties. This interspecific social behaviour has recently been studied empirically and appears to be a form of positive communication for cats, who are more likely to approach a previously unfamiliar human after such interactions. We investigated whether slow blinking can also affect human preferences for cats in a shelter environment. We measured whether cats’ readiness to respond to a human-initiated slow blink interaction was associated with rates of rehoming in the shelter. We also examined cats’ propensity to slow blink when they were anxious around humans or not. We demonstrated that cats that responded to human slow blinking by using eye closures themselves were rehomed quicker than cats that closed their eyes less. Cats that were initially identified as more nervous around humans also showed a trend towards giving longer total slow blink movements in response to human slow blinking. Our results suggest that the cat slow blink sequence is perceived as positive by humans and may have a dual function in cats, occurring in both affiliative and submissive situations. Abstract: The process of domestication is likely to have led to the development of adaptive interspecific social abilities in animals. Such abilities are particularly interesting in less gregarious animals, such as cats. One notable social behaviour that cats exhibit in relation to humans is the slow blink sequence, which our previous research suggests can function as a form of positive communication between cats and humans. This behaviour involves the production of successive half blinks followed by either a prolonged narrowing of the eye or an eye closure. The present study investigates how cat (n = 18) slow blink sequences might affect human preferences during the adoption of shelter cats. Our study specifically tested (1) whether cats’ propensity to respond to human-initiated slow blinking was associated with their speed of rehoming from a shelter environment, and (2) whether cats’ anxiety around humans was related to their tendency to slow blink. Our experiments demonstrated that cats that showed an increased number of and longer eye closures in response to human slow blinks were rehomed faster, and that nervous cats, who had been identified as needing desensitisation to humans, tended to spend more time producing slow blink sequences in response to human slow blinks than a non-desensitisation group. Collectively, these results suggest that the cat slow blink sequence is perceived as positive by humans and may have a dual function—occurring in both affiliative and submissive contexts. Keywords: human-animal interactions; facial expressions; cats; slow blink Animals 2020, 10, 2256; doi:10.3390/ani10122256 www.mdpi.com/journal/animals Animals 2020, 10, 2256 2 of 11 Animals 2020, 10, x 2 of 11 1.1. Introduction Introduction HumanHuman attitudes attitudes towards towards animalsanimals cancan be described in terms terms of of two two primary primary dimensions—affect dimensions—affect andand utility utility [ 1[1].]. 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Thus, further could shed light on the social function of positive communication, specifically in the context of our investigation into cat–human positive communication could shed light on the social function of relationship with felines. positive communication, specifically in the context of our relationship with felines. One cat-human signal that has recently been documented scientifically is the slow blink sequence. One cat-human signal that has recently been documented scientifically is the slow blink Cat slow blink sequences involve narrowing of the eye aperture, specifically consisting of a series sequence. Cat slow blink sequences involve narrowing of the eye aperture, specifically consisting of of shorter half blinks, followed by either a stable narrowing of the eye or a prolonged eye closure a series of shorter half blinks, followed by either a stable narrowing of the eye or a prolonged eye (see Figure1). 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