Tail wagging is a conspicuous behaviour in domestic dogs (Canis familiaris).
Despite how much meaning humans attribute to this display, its quantitative
description and evolutionary history are rarely studied.We summarize what
is known about the mechanism, ontogeny, function and evolution of this
behaviour. We suggest two hypotheses to explain its increased occurrence
and frequency in dogs compared to other canids. During the domestication
process, enhanced rhythmic tail wagging behaviour could have (i) arisen as
a by-product of selection for other traits, such as docility and tameness, or
(ii) been directly selected by humans, due to our proclivity for rhythmic
stimuli. We invite testing of these hypotheses through neurobiological and
ethological experiments, which will shed light on one of the most readily
observed yet understudied animal behaviours. Targeted tail wagging
research can be a window into both canine ethology and the evolutionary
history of characteristic human traits, such as our ability to perceive and
produce rhythmic behaviours
