Should you bring a shopping list when heading to the store or trust your memory?
Researchers at four universities partnered on a study to answer this question. They observed more than 700 consumers in different scenarios, and their findings are available online in the Journal of Consumer Psychology. Their results suggest that shoppers should bring a list to minimize the chances of returning home only to find they forgot something.
In one experiment, the investigators gave people a list of 10 to 20 fruits and vegetables. Half of the participants received a list with familiar items such as apples, bananas and broccoli, while the list for the other half included uncommon items like beetroots, coconuts and figs.
The researchers discovered that when people were shopping for things they don't buy regularly, they had better success remembering everything if they walked through all the aisles rather than relying on memory.
"For unusual purchases, this is a more effective approach because seeing the product will trigger the memory," said Daniel Fernandes, an assistant professor of marketing at Catholic University of Portugal.
If people in the study were buying familiar items, there was no need to cruise all the aisles. They could successfully rely on memory and go directly to the items.
The investigators were also eager to find out if people could predict how many items on the list they would remember to buy once they started shopping after they spent 10 minutes reading a story.
"One of our key findings is that people don't correctly anticipate when they are more likely to forget items," Fernandes said. "When we have something in our mind, it is hard to imagine that we will forget it."
This failure to predict our forgetfulness suggests that people should always bring a shopping list, he explained. Although this may seem like an intuitive solution, statistics show that only about half of shoppers use lists.
These findings could also have broader implications for performance at work. "We often rely on our memories to perform familiar tasks at work, and those tasks will come easily to mind, but unfamiliar tasks are hard to recall," Fernandes said. "To maximize our effectiveness on the job, it's important to pay special attention to those less familiar tasks and put them on the agenda."
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