Is the dog-human relationship an attachment bond? An observational study using Ainsworth's strange situation

Ainsworth's 'strange situation' procedure was used to investigate the dog (Canis familiaris) - human relationship. 38 adult dog-owner pairs were observed in an unfamiliar room, introduced to a human stranger and subjected to four short episodes of separation. The procedure and behavioural analyses were as similar as possible to those used in studying human infants, except for the inclusion of an extra separation period in which the dogs were left alone in the room with articles of clothing belonging to the owner and stranger. A secure base effect was suggested by the fact that the dogs accepted to play with the stranger more in the presence of their owner than during his or her absence. They also explored more in the presence of their owner, but this appeared to be due to diminishing curiosity over time rather than a secure base effect. The dogs also exhibited a range of attachment behaviours, i.e. search and proximity seeking behaviours when separated from their owner, including following, scratching and jumping up on the door, remaining oriented to the door or the owner's empty chair and vocalising. They also greeted their owner more enthusiastically and for longer durations compared to the stranger. Finally, they contacted the owner's clothing more often and for longer durations compared to the stranger's clothing and spent more time next to the owner's chair when the owner's objects were present. Hence, the dogs' behaviour in the strange situation was very similar to that reported in human infants and chimpanzees. However, despite conducting detailed behavioural analyses, the order effects inherent in Ainsworth's procedure prevented the study from providing conclusive evidence that the dog-human bond constitutes an attachment.