Greatest Mysteries: Why Do We Desire Things?

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Editor's Note: We asked several scientists from various fields what they thought were the greatest mysteries today, and then we added a few that were on our minds, too. This article is one of 15 in LiveScience's "Greatest Mysteries" series running each weekday.

Chocolate, vanilla or strawberry? The question of why we want the things we want elicits impassioned answers from scientists in a number of different disciplines, but some argue we’re still a long way away from understanding our desires and preferences in any meaningful way.

We may be able to predict how we will behave in particular conditions, or know that clear preferences emerge in certain situations, but we know very little about where these inclinations come from in the first place, according to one social scientist.

For instance, New York University sociologist Dalton Conley contends that despite decades of research, experts still know little about what truly drives our desires.

“I think the answers out there right now offered by a variety of fields are too facile—they’re actually tautological,” or logically circular truisms that reveal nothing, Conley told LiveScience.

The root of the problem

Sociologists, evolutionary psychologists and economists all have different ideas about what drives our preferences, Conley said, yet none really get to the bottom of the issue.

For instance, it’s easy to come up with evolutionary explanations for our preferences after the fact, Conley said. “You can spin an evolutionary argument for pretty much anything that you see,” he contended, making it “more of a rationalization than a testable hypothesis.”

Evolutionary psychologist Gad Saad from Canada’s Concordia University, who has recently published a book, “The Evolutionary Bases of Consumption,” agrees that the problem is complicated. There is a difference, he explained, between understanding how a mechanism operates and why it occurs.

We might know that a woman’s food preferences change according to where she is in her menstrual cycle, he said, but understanding why our preferences change in this way is an entirely different issue.

Set from birth?

Saad is, however, certain that biology drives most of what we do.

“Contrary to what social scientists think—that we’re born with empty minds—I argue for the exact opposite causal mechanism,” Saad said in a telephone interview.

Yale social scientist Joseph Simmons agrees that biology is a big piece of the puzzle. “We don’t learn to fear electric shocks or loud noises or even threatening faces, but rather, these preferences seem innate,” he told LiveScience.

Shaped by surroundings

But Simmons argues that experience plays a large role in molding what we want, too.

For instance, he said, preferences can be shaped if an experience is accompanied close in time by one that is strongly liked or disliked.

“One reason why advertisers often use humor, sex and other emotionally evocative stimuli in their advertisements is because of the assumption that the company will benefit from its association with those stimuli,” Simmons said.

Preferences also change according to a person’s state of mind and mood. A woman is more likely to buy The Economist magazine when she is thinking of herself as a businesswoman, he said, but more likely to buy Cosmopolitan if she thinking of herself primarily as a female, he said.

Unanswered questions

Simmons says that one big remaining question concerns how social context influences desire.

“We are beginning to understand how word-of-mouth shapes preferences and fads, but there is still a tremendous amount to learn,” he said.

Conley, the NYU sociologist, argues that these kinds of questions beg for carefully designed experiments and a willingness for social scientists, psychologists and neuroscientists to work together to arrive at interdisciplinary answers.

To do this, we need to bring these disciplines physically closer together, agreed Simmons. These scientists need to begin attending the same conferences, publishing in the same journals and speaking the same language, he said.

That is, of course, assuming that these questions can ultimately be answered, noted Conley.

“It might be like quantum physics—it might be unanswerable,” Conley said.

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