02/10/2012 10:15 am ET

Chocolate Study Shows 'Last' Experiences Are More Pleasurable

Sweet on science? You'll want to know about a yummy new study in which researchers used Hershey's Kisses to examine the provocative question: "Is the last always judged to be the best?"

Scientists at the University of Michigan gave students a handful of different flavored chocolates, one at a time, at random. Half of the students were told "Here is the last one," before receiving the fifth and final chocolate. The other half were told, "Here is the next one."

Researchers found that the fifth chocolate was rated as much more enjoyable when it was the "last" chocolate, versus when it was just the "next" chocolate. It was also rated as the favorite 64% of the time, no matter the actual flavor. The finding suggests that people do derive more pleasure from "lasts" than experiences that they don't expect to be their last.

What explains this so-called "positivity effect?" Scientists have a few theories.

“It’s something motivational,” said study co-author Ed O’Brien, a psychology graduate student at the university, in a written statement. “You think: ‘I might as well reap the benefits of this experience even though it’s going to end,’ or ‘I want to get something good out of this while I still can.’”

But O'Brien offered another possible explanation: “Many experiences have happy endings – from the movies and shows we watch to dessert at the end of a meal – and so people may have a general expectation that things end well, which could bleed over into these insignificant or unrelated judgments.”

But if you're thinking it's a silly little chocolate study, think again. The researchers said the finding could explain the way teachers grade the last exams they give, or how employers size up the last applicant for a job. Being aware of the positivity effect could provide a leg up in certain situations.

The study is published in Psychological Science.