Since 1977, the American Temperament Test Society has been conducting a Temperament Test for dog breeds. The purpose of the test is to measure “stability, shyness, aggressiveness, and friendliness as well as the dog’s instinct for protectiveness towards its handler and/or self-preservation in the face of a threat.”
The test simulates a walk through a neighborhood or park where various situations occur. The dog experiences visual (umbrellas suddenly opening), auditory (hidden, unusual noises), and tactile (varying surfaces) stimuli to challenge their composure. They also encounter friendly, neutral, and aggressive strangers. Failure means the dog showed unprovoked aggression, panic without recovering, or intense avoidance and fear.
The following infographic by AAAStateofPlay.com charts out 114 dog breeds ranked by temperament.
[Click image for full size version]