Each time one of our sons comes through the front door our dog gives this huge welcome home. She runs around whimpering and whining, jumping on the furniture, stopping by them to get a recognition pat on the head then runs another circle demonstrating her excitement. When she really gets excited she will even stop for a moment and give them a bark. This carries on for about a minute. We thought at first it was just excitement for the individual but soon she started even doing it for sons which only show up about twice a year. Then she started doing it for all the grand kids both boys and girls.
Since dogs are pack animals we think she is welcoming home her pack. She also quickly puts them in pack order and snubs the ones she feels are beneath her status. How she established the status we do not know but she has developed a distinct pecking order.
She does get excited to see most of our friends but as the saying goes, “blood is thicker than water”, or so it seems with our dog. She certainly seems to understand bloodlines.