Today’s best managers know that employees can process information at varying speeds. For example, employees will process, or think through and make conclusions about, information that is positive faster than they will process negative information. This happens because employees have much more positive information about themselves stored in their brains than they do negative information. When employees hear positive information, then this new positive information quickly matches up with the positive information that is already there. This employee tendency helps explain why employees rapidly absorb positive feedback, but then take more time to process negative feedback.
Source: Unkelbach, C., Fiedler, K., Bayer, M., Stegmueller, M., & Danner, D. 2008. Why positive information is processed faster: The density hypotheis. Journal of Personality and Social Psychology, 95, 36-49.