Tone, though easily confused with mood, refers to an author's "perspective or attitude" toward a subject, whereas mood refers to the emotions the author evokes in the reader through content due to the author's own emotions on the subject (Literary Devices, "Tone"; "Mood"). Examples of words used to describe tone are apathetic, authoritative, ironic, instructive, reflective, and questioning. Malcolm Gladwell certainly uses several tones to convey the arguments in his book Blink: The Power of Thinking Without Thinking, three of those tones being ironic, informative, and persuasive.
Gladwell uses an ironic tone as early as his introduction. Here, he goes to great lengths to describe in detail the California J. Paul Getty Museum's ironic purchase of a Greek statue from the 6th century BC called a kouros. The museum had devoted 14 months to investigating the authenticity of the statue before committing to the purchase. The investigation included dating the statue using core samples, tracing the documentation of previous owners, and even soliciting the opinions of experts in Athens.
However, sadly, the first time it went on display in 1986, viewer Federico Zeri, an Italian art historian, knew instantly that something was off about the statue's fingernails though he couldn't express it in words. Similarly, Evelyn Harrison, one of the world's top experts in Greek sculptures, expressed disappointment in the museum having purchased the statue, though she too could not articulate in words what about the statue disappointed her. Finally, when Thomas Hoving, a previous director of New York City's Metropolitan Museum of Art, saw the statue, the first word that popped into his mind was "fresh," which he noted is not a suitable word to describe an ancient statue.
Gladwell compares the instantaneous conclusions these three experts drew about the statue against the 14-month-long investigation into the statue performed by so-called experts to express the ironic truth that people are perfectly equipped to reach accurate, advantageous, and even lucrative conclusions in only a moment. He further expresses the irony that extensive investigations like the one above only serve to muddy the waters. Hence, as we can see, Gladwell clearly used an ironic tone to express the ironic truths he wanted to convey and state his argument that it only takes two seconds for people to draw correct conclusions.
Gladwell uses the rest of the chapters in his book to do several things. First, he explains the theory of "thin slicing," which is the theory that people are able to accurately develop conclusions based on very tiny details. Second, he discloses exactly why many of us are unable to explain our intuitions in words. Third, he explains that prejudices interfere with our true intuition. The book is also full of various examples of individuals using their intuition to their advantage. Hence, the essential purpose of the remaining chapters of the book is to both explain and prove the argument he made in the introduction concerning mankind's ability to intuitively draw correct conclusions in only two seconds. Since Gladwell's purpose is to explain and prove, we can easily see that his most frequently used tone in the remainder of the book can be classified as both informative and persuasive.