Table 1.

Description of the strange situation test procedure

Episodes	Episodes labels	Description
Episode 1: Dog and Owner	1-DO	The owner sat quietly reading a magazine and the dog was free into the room
Episode 2: Dog, Owner, and Stranger	2-DOS	The stranger entered the room, sat quietly for 1 minute, talked with the owner for the second minute, approached the dog, and attempted to stimulate play during the third minute. At the end of this episode, the owner left the room unobtrusively
Episode 3: Dog and Stranger (1st separation episode)	3-DS	The stranger continued to play with the dog if it was willing; if it was inactive or distressing, the stranger attempted to distract it with play or by providing verbal and tactile comfort
Episode 4: Dog and Owner (1st reunion episode)	4-DO	The owner entered the room and greeted and/or comforted his/her dog as usual after returning from work or shopping, while the stranger quietly left the room. The owner was free to play with the dog throughout the episode. At the end of this episode, the owner left the room
Episode 5: Dog alone	5-D	The dog remained alone for three minutes
Episode 6: Dog and Stranger (2nd separation episode)	6-DS	The stranger entered the room and followed the same procedure as in episode 3
Episode 7: Dog and Owner (2nd reunion episode)	7-DO	The owner entered the room greeted and followed the same protocol as in episode 4, while the stranger left the room