Dogs are like people in at least one respect. Dogs like some people and do not like other people. The difference is probably based on smell and may have a lot to do with how the dog interprets the body movements, facial expressions, hand movements, and voice patterns of a given individual. The behavior may be in part related to how one given individual relates to the dog’s owner. If a person is friendly with the dog’s owner then the dog usually likes the other person.
This may be the result of thousands of years of behavioral training that has occurred between dogs and people or it may just be a natural dog thing. This little video is a perfect example. Joshua’s dog simply adores the garbage man. According to Joshua and the video, the dog waits for the garbage man every week. Science has shown that dogs know what time of day it is but no one knows exactly how they know.
The garage man drives up in a big orange truck. The dog literally bounds over to greet the man joyfully and excitedly when he gets out of the truck to get the garbage. The dog obviously knows the man and the man knows the dog. The dog gets a little petting and some love from his weekly friend.