In late August, Erin Alexander, 57, sat in the parking lot of a Target store in Fairfield, Calif., and wept. Her sister-in-law had recently died, and Ms. Alexander was having a hard day. A barista working at the Starbucks inside the Target was too. The espresso machine had broken down and she was clearly stressed. Ms. Alexander who'd stopped crying and gone inside for some caffeine " smiled, ordered an iced green tea, and told her to hang in there. After picking up her order, she noticed a message on the cup: "Erin," the barista had scrawled next to a heart, "your soul is golden." The warmth of that small and unexpected gesture, from a stranger ... moved her deeply. New findings, published in the Journal of Experimental Psychology in August, corroborate just how powerful experiences like Ms. Alexander's can be. Researchers found that people who perform a random act of kindness tend to underestimate how much the recipient will appreciate it. And they believe that miscalculation could hold many of us back from doing nice things for others more often. "People tend to think that what they are giving is kind of little, maybe it's relatively inconsequential," [study co-author Amit] Kumar said. "But recipients are less likely to think along those lines. They consider the gesture to be significantly more meaningful because they are also thinking about the fact that someone did something nice for them." What skills and talents do you already have? And how can you turn that into an offering for other people?"