What's the Psychology Behind Our Collective Love of Crunch?

My wife and I have very different reactions to mediocre restaurant meals. I will scrape off offending sauces, eat more bread, and glumly make a go of my meal. She will push her plate away and stop eating—that is, until we get home and I hear the telltale keeee-runch coming from the kitchen after she rips into a bag of potato or corn chips. Sometimes I think she finds as much satisfaction in the sound...