One is anticipated life events, two: unexpected life events, and three: accumulated life events. Everyday hassles are the main psychologists who study emotions and stress, calling these irritating and frustrating incidents that occur in our daily transactions with the environment. 5.) Cognitive appraisals are important because what causes us stress is not the event that happens, but how we perceive or evaluate the event/situation. To feel stress, there are two necessary things to consider. The first is to perceive that some sort of question or threat is present. The second is to conclude that you may not have the resources available to address that particular threat. The reaction we have to stressful situations is to evaluate the situation in terms of whether it harms, threatens or tests our physical or psychological.