There is an increasing scientific agreement that the origin of the domestic dog dates back several tens of thousands of years. In fact, the history of dog is a history of unique behaviour evolutionary process in which they have gradually become adapted to human environment and, as a result, became sensitive to human social signals (Hernádi et al 2012; Miklósi & Topál 2013). Human social environment provides a natural niche for dogs (Miklósi 2007) who seem to be predisposed to develop close contact with humans (Gácsi et al 2005). It has been reported (e.g. Palmer & Custance 2008; Gácsi et al 2013) that the relationship between a dog and its owner fulfils the behavioural criteria of attachment (c.f. Ainsworth 1969; Rajecki et al 1978) in many respects (e.g., contact seeking with the owner in emotionally distressing situation, using the owner as a secure base) which paved the way for the development of socially competent communicative interactions and synchronised collaborative activities between dogs and their human companion.
In line with this, several studies have provided empirical evidence for inter-specific social skills in dogs (e.g. Hare & Tomasello 2005). Dogs have been reported to be especially skilful in reading the expression of human communicative intent (i.e. name calling, eye-contact - Téglás et al 2012), and in utilizing directional gestures including gaze-alternation (Soproni et al 2001) and different types of pointing gestures (Soproni et al 2002). They are also able to differentiate human emotions (Turcsán et al 2014) and show emphatic-like response toward their owners (Custance & Mayer 2012).
Experiments presented in the current doctoral dissertation were designed on the basis of the idea that domestic dog is a particularly human-tuned social animal, whose behaviour has been largely shaped, both evolutionary and developmentally, by the human.
In the first study (Study 1) we investigated the details of how dogs’ perseverative search error can be affected via human communicative signals in hide-and-search tasks. In Study 2 we experimentally tested the widely held notion that dogs’ behavioural responses in task situations are under the influence of their owner’s emotions. Next we focused on the special case of social influence, the placebo effect. Placebo effect in humans is mostly fuelled by social influence via suggestions (e.g. verbal information from a trustworthy, certified person - Kirsch 1999) but it can also stem from simple associative learning processes (conditioned placebo effect –McMillan 1999). Based on its interspecific social skills and its capacity to be socially influenced by humans, we hypothesized that dogs are susceptible to placebo effect.
In the subsequent studies, therefore, we investigated various aspects of this phenomenon in family dogs; in Study 3 we demonstrated the existence of conditioned placebo effects in dogs and then (in Study 4) we also tested how dogs can be influenced by their owners’ expectations about the test situation.
Before providing the details of experimental investigations, in the next parts of the introduction (1.1., 1.2., 1.3.) we give a short overview of the evidence about dogs’ sensitivity to human communication and their susceptibility to emotional contagion and we also provide a description of placebo effect and its relevance to nonhuman animals.
Mason N McLary
|Publisher||Eötvös Loránd University|
|Location of Publication||Budapest, Hungary|
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