Calming signals is a term conceived by Norwegiandog trainer and canine ethologist, Turid Rugaas, to describe the patterns of behavior used by dogs interacting with each other in environments that cause heightened stress and when conveying their desires or intentions.[1][2] The term has been used interchangeably with "appeasement signals."[3][4] Calming signals, or appeasement signals, are communicative cues used by dogs to de-escalate aggressive encounters or to prevent the development of aggressive encounters completely.[5] Calming signals are performed by one dog (the sender) and directed towards one or more individual(s) (the recipient(s)), which could be dogs or individuals of other species, such as humans.[4] When calming signals are ignored, a dog may display warning signals of aggression, and this has the potential to escalate to outright conflict between individuals.[6]
The domestication of dogs by humans has significantly altered the behavioral patterns observed in ancestral species, such as the wolf (C. lupis).[4] Dogs have developed changes in body language, as well as changes in auditory and olfactory displays over the course of some 30,000 years, and many of these modified behavioral patterns, or calming signals, can differ in meaning depending on the intended signal receiver's species.[7] Calming signals can be released by an individual voluntarily, or they can be an involuntary response to environmental stimuli as a result of stress-induced changes to body chemistry, such as the release of an odour from the body when anxious.[7]