There is an international rule that babies are cute. Of course, this is not always actually true, but we say all babies are cute as a kind of acceptable lie. Many babies in fact look like little old people – but then, little old people are considered cute and given all kinds of special permission to break social norms. Except for dirty Frenchmen. It doesn’t matter how old they are, they still think they have a chance, so you can’t afford to let them hit on you.
There are also the related corollaries that have to do with certain features of the infants resembling that of their parents or grandparents. While others (thank you, Sarah) may think this is just an accepted lie perhaps to assure the legitimacy of fatherhood, there are other possible reasons behind the early commentary. An offhand example is the ‘got your nose’ game. What child would realistically ever be fooled that his uncle’s visible nose was replaceable with his own cute little button unless he’d heard from infancy that he had Uncle Hershel’s snoz?
But what I’d really like to mention is the puppy corollary. Even the word itself is cute – ‘puppy!’ How can an infant dog not be adorable, even if it does grow up into a disgusting-looking bulldog? I mean, look at those biggly paws! And this really applies to the entire animal kingdom. Baby polar bear? Cute. Baby panda? Cute (I have video evidence I’ll try to include later). Baby giraffe, all gangles and purple tongue? Still cute.