Dogs are genetically programmed to show affection to the creature they think are their pack leaders. They are genetic suck ups whose greatest goal in life is to find something disgusting to roll in.Cats are solitary creatures by nature, and ounce for ounce are much smarter than dogs. They appreciate humans just because they like them, not because nature programmed them to do it. When a cat gets in your lap, turns his purr box on, and closes his eyes to slits, then you KNOW you’ve been loved just for being you. The occasional hairball or dead mouse liver on the doorstep is a small price to pay.