Kunkel, a communications consultant, posits that the most persuasive and powerful icons and brands owe their success to an uncanny ability to appeal to one or more cultural and biological universals, our species' emotional and behavioral responses to certain stimuli (for example, the need for security and comfort, distrust of classically beautiful people). Unfortunately, Kunkel's evidence of these universals is vague and speculative?referring to research into the effect of sound waves on cellular structure, she asserts that just as plants dislike heavy metal music and uncooked rice thrives on compliments, our body processes are altered by sound waves?and she advises her readers to speak in rhythms that resonate on a cellular level.