Anybody who has ever been inside a supermarket has encountered greater variety in five minutes than Marco Polo was exposed to in a lifetime. Hundreds of breakfast cereals stand across the aisle from as many different cookies, including enough subspecies of chocolate chip to provide the adventurous a new type each day of the month.
But that's just the start: The average grocery store stocks 30,000 distinct items, of which 20,000 are unceremoniously dumped and replaced annually.
Had Marco Polo had access to a PathMark or a Safeway, he could have been a world-class explorer without traveling anywhere. (For breakfast alone, he could have discovered seven kinds of Cheerios.) With so many options to choose from, the poor man would scarcely have had time to get out of town.
Time is only one of many hidden costs of abundance to our society, according to Swarthmore social psychologist Barry Schwartz in his intermittently brilliant sixth book, "The Paradox of Choice."
"As a culture, we are enamored of freedom, self-determination, and variety, and we are reluctant to give up any of our options," he writes with characteristic directness. "But clinging tenaciously to all the choices available to us contributes to bad decisions, to anxiety, stress, and dissatisfaction - even to clinical depression."
Were life limited to shopping for chocolate chip cookies and Cheerios, such a claim might seem exaggerated, if not absurd. But, as Schwartz ably documents, we enter an equivalent supermarket of options when deciding where we want to live, for whom we want to work, and even how we want to look. While few have complete autonomy, a combination of technological efficiency and laissez-faire morality have opened more choices to more Americans than ever before.
The report that more Americans are also more unhappy than ever before might simply be a perverse coincidence. We may even question the statistics: As the social stigma associated with depression decreases, people may be more open about their listlessness. They may even feel encouraged to consider themselves depressed as the subject receives so much attention in the media.
Yet, the case Schwartz makes for a correlation between our emotional state and what he calls the "tyranny of choice" is compelling, the implications disturbing. From unmet expectations to regret over the road not taken, the perils of living in a multiple-choice society rival in number the variety of snacks in the largest grocery store.
Driving this malaise is the problem that "everything suffers from comparison." Schwartz describes a simple experiment in which people are asked whether they'd rather be given $100 outright, or gamble on winning $200 at the toss of a coin. That the vast majority would prefer the $100 may seem strange at first: A 50 percent chance of earning $200 is mathematically equivalent to a 100 percent chance of earning $100. Half the people asked ought to opt for the coin toss. However, the alternatives are not psychologically equivalent: Getting twice the money is not twice as pleasurable. The distance between zero and 100 is subjectively greater than the distance between 100 and 200.
Economists capture this phenomenon in the law of diminishing marginal utility (and provide us the formulae to calculate that, psychologically, we'd need winnings of $240 to be equally tempted by the coin toss). How, though, does this asymmetry relate to real-life choices? If losses subjectively weigh more heavily than gains, the advantages of any chocolate chip cookie or career path we select will count for less than those of the options we pass up.
"Ultimately, the quality of choices that matters to people is the subjective experience that the choices afford," Schwartz points out. "And if, beyond a certain point, adding options diminishes our subjective experience, we are worse off for it."
What are we to do? Schwartz thinks he has some answers. However, while shrewdly avoiding the age-old call to turn back the hands of time, he stumbles instead headlong into the abyss of gratuitous self-help.
"Regret less," he tells us in a final chapter that is itself regrettable at the end of such an insightful book. "Practice an 'attitude of gratitude.' " As is true of the self-help category generally, one's ability to follow these little aphorisms is inversely proportional to one's need to hear them.
Schwartz's mistake is to assume that we need answers, an abundance of them, and that such solutions can be produced and consumed as easily as breakfast cereals. While that notion may sell books, the enduring value of "The Paradox of Choice" will be found in the questions it raises that cannot be directly addressed and summarily dismissed.
• Jonathon Keats is a freelance reviewer in San Francisco who serves on the board of the National Book Critics Circle.