Comment on "Human-directed attachment behaviour in wolves suggests standing ancestral variation for human-dog...

In their recent paper, Hansen Wheat et al. (Ecology and Evolution, 2022, 12, e9299) claimed that hand raised 23-week-old wolves showed the same attachment behaviour towards their handler in the Strange Situation Test (SST) (Determinants of infant behavior, 1969, 4, 111) as dogs. At first glance, their results seem to contradict previous findings that domestication caused a unique change in social-affiliative behaviours in dogs (Animal Behaviour, 2005, 70, 1367). We argue that no persuading evidence was presented to claim that "wolves can show attachment behaviours towards humans comparable to those of dogs". When dealing with a behaviour system (Child Development, 1977, 48, 1184), the subjects' behaviour must meet consistent criteria (Behavioural and Brain Science, 1978, 3, 417), and a few behavioural preferences should not be used to claim the presence of an attachment system, especially, if the experiment violates basic assumptions of the original test. We believe the intriguing scientific question is whether the dog-owner relationship is qualitatively different from what could be observed in the wolf-hand raiser relation. Assessing all available data, our answer is still yes; dogs are unique in this respect.