It takes letters to make words. Memorable shapes, graceful vowels or forceful consonants. The magic letter K —why does the K sound produce a slight smile? It could be “Facial Feedback.” Many words featuring the sound K force the lips to turn up at corners, and the face smiles. Say “duck” or say “quack”, fun huh? Possibly this is why we associate the sound K with happiness. It’s the contagious nature of a happy face, no matter how low brow. People easily smile when they feel happier. However, the mechanism also works in reverse…maybe people feel happy simply because they have smiled. Either way, Joe Penner, a radio comedian, made himself pretty darn famous with a ducky tag line, “Wanna Buy a Duck?” That was in the 1940s, of course.
By the way, what does the English language have against the letter D? It appears to have a nice straight backbone and a curvaceous front contour but still so many words that begin with a D are downers. Disaster, dispirited, despise, doldrums, downcast, despondent, dull, dejected, death, debility, decay, defame, defile, disadvantage, disdain, disgrace, doom, downfall, dying, —enough, already.