Kendall Shanks chewed on a few grains of rice like she was working on a porterhouse steak. Her mother, Brenda Cook, was astonished. "Oh my gosh! Look at Kendall!" her mother cried, maybe just a little too loud for a restaurant. As the 2 1/2-year-old continued her vigorous efforts, Mom pretended to chew with cartoonish exaggeration and praised her daughter more boisterously. "Kendall's such a big girl!" she said, her eyes filling with tears. She and Kendall's dad, James Shanks, giggled at their toddler's performance. It was only later they wondered what other diners thought of their response to a...