Dogs may prefer quiet, soothing sounds. Harsh or loud voices may scare them.
Dogs may perceive certain attitudes as dangerous or appealing. Slow, soft approaches may be seen as friendlier, while rapid moves or looming postures may evoke dread or defensiveness.
Routine and consistency please dogs. Regular good contact with people who feed, play, or walk them may make them more comfortable.
The breed and socialization of a dog might also affect their preferences. Some breeds are naturally more friendly, while others are more shy around strangers.
Finally, dogs have ancestor-inherited instincts. These habits can affect their reactions to certain people based on minor clues that trigger their impulses to approach or avoid threats.