Sentiment Patterns

Even apart from the instability due to speculation, there is the instability due to the characteristic of human nature that a large proportion of our positive activities depend on spontaneous optimism rather than mathematical expectations, whether moral or hedonistic or economic. Most, probably, of our decisions to do something positive, the full consequences of which will be drawn out over many days to come, can only be taken as the result of animal spirits—a spontaneous urge to action rather than inaction, and not as the outcome of a weighted average of quantitative benefits multiplied by quantitative probabilities.

Human action is, in a great extent, predictable. Humans arerational and endowed with the ability to weigh benefits and costs in search forthe best possible expected outcome. Despite this straightforward evidence, in many circumstances involving decision-making there are evident departures relatively to the strict rational behavior. The complexity of the problems faced by individuals often compels them to adopt simple heuristics, to engage in strategic complementarities and to decide based on instincts or sentiments.