Dogs displaying excessive friendliness toward complete strangers—launching themselves at unfamiliar people, soliciting attention from anyone within range, treating every human encounter as a reunion with a long lost family member—aren't exhibiting poor training or behavioral problems. They are expressing a genetic modification to the social brain so fundamental it represents one of the most significant neurological differences between dogs and their wolf ancestors. Research comparing dog and wolf genomes identified specific mutations in genes associated with human Williams syndrome, a condition causing humans to display indiscriminate friendliness, reduced social fear, and intense desire for human connection regardless of familiarity. Dogs carrying these genetic variants show measurably reduced amygdala reactivity toward strangers, meaning the threat assessment system that makes wolves and many other animals appropriately cautious around unfamiliar individuals is neurologically dampened in domesticated dogs, particularly in breeds selected across generations for human sociability. Certain breeds amplify this baseline friendliness through additional selective pressure. Labrador Retrievers, Golden Retrievers, and Cavalier King Charles Spaniels were developed in environments requiring constant positive interaction with unfamiliar hunters, handlers, and working partners, layering learned social enthusiasm over already reduced stranger wariness until the resulting temperament registers as almost aggressively affectionate to unprepared recipients. The jumping behavior accompanying excessive friendliness connects to wolf greeting rituals where subordinate pack members lick the mouths of dominant returnees as submission and bonding signals. Dogs jumping toward human faces are executing an ancient social greeting protocol scaled to reach mouth level, their target destination revealing the evolutionary origin of behavior that looks simply like poor manners to modern owners. Overly friendly dogs also demonstrate measurably lower cortisol responses in social situations, experiencing genuine physiological calm around strangers that anxious or reserved breeds...