Garage sale study provides yet another reason to think twice before making a big decision

Conventional wisdom holds that people are easily swayed by first impressions, and there is strong scientific evidence that snap initial judgments are hard to shake, even when they turn out to be inaccurate.

But according to a new study, thinking about it can help us avoid judging a book solely by its cover.

In a study published on September 9 in the Journal of Experimental Psychology: GeneralA team of researchers from Duke University started with an age-old question: Is it better to start strong with a good first impression, or to end on a high note?

To shed light on the problem, they conducted a study of an imaginary garage sale. In a series of online experiments, the researchers asked participants to rummage through virtual boxes of unwanted items looking for items to include in the sale.

Most of the items in each box were not very valuable: an old alarm clock, for example, or a potted plant. A few special items, like a nice lamp or a teddy bear, were worth more.

Participants won real money based on which boxes they chose, so they were motivated to figure out which boxes were the most valuable.

However, unbeknownst to the participants, the total value of the 20 items in each box was the same. It was the order of the “trinkets” and “gems” that varied.

In some boxes, all the valuables were on top, so participants spotted these items first when they unpacked the box. In other boxes, the valuables were grouped in the middle or bottom, and in some boxes, they were mixed together.

After participants opened the different boxes, the researchers asked them to estimate the value of each one and choose their favorite. Some participants judged the boxes immediately, but others “slept on them” and decided after a night’s delay.

A pattern quickly emerged: When participants had to make a decision immediately, they tended to remember and judge the boxes not based on their entire contents, but rather on the first items they encountered.

“We found that people are strongly influenced by first impressions,” said lead author Allie Sinclair, who conducted the research as part of her doctoral degree in the lab of Dr. Alison Adcock, professor of psychiatry and behavioral sciences at Duke.

Repeatedly, participants looked at boxes containing valuable items. When they spotted these “treasures” before the cheap items, they were more likely to choose that box than if they had seen the cheap items first.

Not only did participants consistently choose boxes that “started strong” over others, they also tended to overestimate their value, believing they were worth 10% more than they actually were.

This is an example of a psychological phenomenon called primacy bias, said Sinclair, who is now a postdoctoral researcher at the University of Pennsylvania.

When it comes to forming an overall opinion about something, it turns out that we are unduly influenced by the first piece of information we encounter, even when new facts emerge.

In the garage sale experiment, this bias prevented participants from comparing boxes rationally and even led them to believe that some of them were more valuable than they actually were. At the same time, ironically, they were less able to recall details when asked which items in their favorite boxes were the “treasures.”

However, participants who were not asked to decide until the next day were less likely to fall into these traps.

“They made more rational choices, equally favoring boxes containing groups of valuable items at the beginning, middle or end,” Sinclair said.

Participants who had “slept on it” no longer had an overwhelming preference for boxes that made a good first impression. Boxes that saved the best for last were also weighted favorably in their mental arithmetic.

“Judging by first impressions can actually be a good thing for making choices in the moment,” Adcock said. Say you’re watching the opening scene of a movie or skimming the first few pages of a book. Quick judgments based on those first impressions can help us decide when it might be best to move on before investing too much time and effort.

But when it comes to situations with longer-term stakes — like returning to a restaurant, getting a job or dating someone — “there’s wisdom in the idea of ​​’sleeping on it’ before you make a decision,” Sinclair said.

“This is an exciting first look at how our brains summarize a rewarding experience,” Adcock added. “Once the experience is over, our brains put all the information together in memory to help us make better choices – and this trick happens overnight.”