According to cognitive appraisal theory, emotion in an indi-vidual is the result of how a situation/event is evaluated by theindividual. This evaluation has different outcomes among peo-ple and it is often suggested to be operationalised by a set ofrules or beliefs acquired by the subject throughout develop-ment. Unfortunately, this view is particularly detrimental forcomputational applications of emotion appraisal. In fact, it re-quires providing a knowledge base that is particularly difficultto establish and manage, especially in systems designed forhighly complex scenarios, such as social robots. In addition,according to appraisal theory, an individual might elicit morethan one emotion at a time in reaction to an event. Hence, de-termining which emotional state should be attributed in rela-tionship to a specific event is another critical issue not yet fullyaddressed by the available literature. In this work, we showthat: (i) the cognitive appraisal process can be realised withouta complex set of rules; instead, we propose that this processcan be operationalised by knowing only the positive or nega-tive perceived effect the event has on the subject, thus facili-tating extensibility and integrability of the emotional system;(ii) the final emotional state to attribute in relation to a specificsituation is better explained by ethical reasoning mechanisms.These hypotheses are supported by our experimental results.Therefore, this contribution is particularly significant to pro-vide a more simple and generalisable explanation of cognitiveappraisal theory and to promote the integration between theo-ries of emotion and ethics studies, currently often neglected bythe available literature.