It’s often said that first impressions are hard to shake—and now, science backs this up.
According to a recent study by researchers at Duke University, our snap judgments tend to stick, even when they’re inaccurate. However, the research also points to a surprising remedy: taking time to “sleep on it” can help us make more rational decisions.
In an experiment published in The Journal of Experimental Psychology: General, participants were asked to virtually browse through boxes of items for an imaginary garage sale. Each box contained a mix of low-value and high-value items, such as a potted plant versus a valuable lamp. But here’s the catch: the overall value of the items in each box was identical. The only difference was the order in which the “junk” and “gems” appeared.
As expected, when participants made quick decisions, they consistently chose the boxes where valuable items appeared first. These participants judged the boxes based on initial impressions, believing the ones that “started strong” were worth more than they actually were—on average, they overestimated the box’s value by 10%. This is a psychological phenomenon known as primacy bias, where early information weighs more heavily in our overall evaluation.
The intriguing part? Participants who were given a night to think about it made more rational decisions. They evaluated the boxes more fairly, regardless of whether the valuable items appeared at the beginning, middle, or end. In short, “sleeping on it” helped them avoid the bias of first impressions.
Lead researcher Allie Sinclair, who conducted this study as part of her Ph.D. at Duke, explains that first impressions can sometimes serve us well. For instance, if you’re deciding whether to continue watching a movie based on its opening scene, quick judgments can help save time. But for decisions with longer-term consequences—like choosing a new restaurant or making hiring decisions—it pays to take a step back and allow time for reflection.
Sinclair and her team concluded that when we delay decision-making, our brains can better piece together the entire experience and help us make more informed choices. This research provides valuable insight into why we’re so easily swayed by first impressions—and how taking a little extra time can lead to better decisions.