In one test, participants in a happy mood were better able to come up with a word that unified three other seemingly disparate words, such as "mower," "atomic" and "foreign." Solving the puzzle required participants to think creatively, moving beyond the normal word associations--"lawn," "bomb" and "currency"--to come up with the more remote answer: "power."via SciAm
Interestingly, induced happiness made the subjects worse at the second task, which required them to ignore distractions and focus on a single piece of information. Participants had to identify a letter flashed on a computer screen flanked by either the same letter, as in the string "N N N N N," or a different letter, as in "H H N H H." When the surrounding letters didn't match, the happy participants were slower to recognize the target letter in the middle, indicating that the ringers distracted them.
The results suggest that an upbeat mood makes people more receptive to information of all kinds, says psychologist Adam Anderson, co-author of the study published online by Proceedings of the National Academy of Sciences USA.