John le Carré wrote this descriptive line in his novel, The Night Manager.
“Madame Latulipe let out the peal of wild laughter that is the signature-tune of humourless people.”
I don't mean to suggest that a lack of humor is a character flaw. I look on it as merely a defect, like baldness or being color-blind. Where the character issue comes in is when a humor-challenged person tries to fake a fairly unfakeable human response.
From the Jon Stewart Show: "Hillary Showcases Her 'Humanity'"
Actually, these are not the best examples of Senator Clinton's odd laughter. In these clips she comes across more like those romantic-comedy film actresses from the early 1960s who get silly from too much champagne.