After decades of thinking about depression, what a relief it is to turn to pleasure! Paul, I envy you for the time you've devoted to sunny aspects of our humanity.
I'm a practicing psychiatrist, not a research psychologist, but as someone who follows the literature on happiness, I'm convinced that How Pleasure Works is a comprehensive and authoritative summary of, to quote the subtitle, "The New Science of Why We Like What We Like." It's also a gracefully written book and a lot of fun, not least because, as the tour guide, you're great company. Who else, considering the ancient philosophical question of what defines the human race, would venture, "Man is the only animal that likes Tabasco sauce?"
Beyond being bold and outlandish, that sort of statement is important because it recognizes that human pleasure is complex. You're moving a step beyond the now-familiar psychology that says we're obese because when our ancestors roamed the grasslands, the survivors were the ones programmed to enjoy sweets, such as ripe fruits, when they were available. Our liking spice might call for a higher-level explanation, perhaps one attentive to concepts like culture and cuisine.
I have questions I'd love to raise about that "new science," but first a word about my response to older approaches. I tend to get grumpy about modern psychology on two counts: It is besotted with Darwin, and it defines the social universe in terms of what is readily measured. The focus on natural selection creates a temptation to conclude that what ever it is (e.g., depression) is good, because it has survived. At the same time, evolutionary psychology compresses the space between modern humans and apes, giving rise to the notion that we're ill-suited to contemporary life. We are, for example, easy prey for marketers, who manipulate us by playing to our instincts. In this sense, whatever is, is bad, because our environment games us.
To the untutored eye, reality is messier. Some common phenomena seem simply harmful. (Yes, I know, evolutionary biology recognizes that possibility, but the temptation is always in the other direction, toward explanation in terms of benefits.) And our distinctly human judgments can be remarkably insightful. Experimental psychology seems to produce a stick-figure version of our doings.
To give an example of what worries me: It's easy to demonstrate that tasters prefer cheap wine when it's presented in fancy bottles. That experiment is cited in almost every overview on the topic of choice. (I'm thinking of three books, each with its virtues, that I've reviewed over the past two years: The Hidden Brain, by Shankar Vedantam; How We Decide, by Jonah Lehrer; and Why We Make Mistakes, by Joseph T. Hallinan.) But what we get wrong is easier to discuss than what we get right. How is it that, when they're not fooled, humans can be oenophiles, discerning and enjoying subtle differences between vintages of burgundy? Why don't we all drink milk or simple syrup? Psychology is less attentive to drinks than to the containers that hold them.
The strength of your book is that you approach pleasure as we experience it, with its many contradictions. Why do we savor foods that burn the tongue? Much of your answer derives from a reasonably new movement in psychology, essentialism. That perspective takes into account the notion that humans go beyond thinking about qualities (like piquancy) to interacting with entities (like home cooking). We believe, as you put it, "that things have an underlying reality or true nature that one cannot observe directly and it is this hidden nature that really matters."
You point readers toward essentialism by getting us to think about a person we adore and then to imagine someone with the same traits, an identical twin who resembles the inamorata in every measurable way. We would not love this second person the way we love our spouse or significant other. At the same time, if our subject is a heterosexual man and the clone is a woman, he might find sex with her kinkier than sex with the wife or girlfriend. You cite an Isaac Bashevis Singer play in which a fool from Chelm gets lost, stumbles back into his own village, sees his dull wife, and, thinking her a new acquaintance, becomes aroused.
The example suggests that we are not attracted to properties only (beauty, intelligence) but to the person who has the qualities—or even to the person as contrasted with other people, the person in the context of our lives. This realization takes us from the easily testable (men desire women whose hip-to-waist ratio suggests health and fertility) to the everyday (this man loves that "funny valentine," whose figure is less than Greek).
Immersion in life at this level, whole people, takes psychology out of its comfort zone. I'm tempted to start by asking you just how far the field has moved in this direction. Is psychology able to transcend studies of packaging and return to a more fundamental consideration of why we take pleasure in Malbec, enchiladas, and good friends?