Sadness is an emotion characterized by feelings of disadvantage, loss, and helplessness. The Wounded Angel (Haavoittunut enkeli (1903 is a painting by Finnish symbolist painter Hugo Simberg. Hugo Simberg ( June 24 1873, Hamina - July 12 1917, Ähtäri) was a Finnish symbolist painter and An emotion is a mental and physiological state associated with a wide variety of feelings thoughts and behaviours When sad, people often become quiet, less energetic, and withdrawn. Sadness is considered to be the opposite of happiness, and is similar to the emotions of sorrow, grief, misery, and melancholy. Happiness is an Emotion associated with feelings ranging from contentment and satisfaction to Bliss and intense Joy. Grief is a multi-faceted response to loss Although conventionally focused on the emotional response to loss it also has physical cognitive behavioral social and philosophical The philosopher Baruch Spinoza defined sadness as the “transfer of a person from a large perfection to a smaller one. Baruch or Benedict de Spinoza (ברוך שפינוזה Bento de Espinosa Benedictus de Spinoza ( November 24, 1632 – February 21, ”
Sadness can be viewed as a temporary lowering of mood (feeling blue), whereas clinical depression is characterized by a persistent and intense lowered mood, as well as disruption to one's ability to function in day to day matters. Major depressive disorder, also known as major depression, unipolar depression, unipolar disorder, clinical depression, or simply depression
Evidence presented by Forgas (1992, 1994) suggests that our mood has an influence on how accurately we evaluate each other. The effect on our accuracy might be a result of faulty information processing where a person may take his current mood as a source of information. Information processing is the change (processing of Information in any manner detectable by an observer. He would then use this biased information as a bases for his evaluation.  For instance, happy people are inclined to evaluate others in a positive way, and sad people are inclined to evaluate people in a negative way.
Sad people have been found to be less accurate than happy people in their evaluations, as well as taking a longer period of time for the evaluation.  Several explanations for this have been postulated:
Sadness may affect a person's social standing.
Studies have found that when people recognize an expressed emotion, they tend to attribute additional characteristics to the person expressing that emotion (Halo effect). An emotion is a mental and physiological state associated with a wide variety of feelings thoughts and behaviours The halo effect refers to a Cognitive bias whereby the perception of a particular trait is influenced by the perception of the former traits in a sequence of interpretations A happy person, therefore is perceived warmly whereas a sad person is perceived as weak and lacking ability and an angry person is perceived as powerful and dominant. (Keltner, 1997).
Tiedens's  study explored whether people provide power to people they like or rather to people they perceive as powerful. The study, which examined social position in political, business and job interview situations, found that people prefer to give status position and power to an angry leader rather than to a sad one. Social position is the position of an Individual in a given Society and Culture. Anger is an emotional state that may range from minor irritation to intense rage People tend to give power to those perceived as powerful instead of to those whom they like. For example, in the business world, a positive statistical correlation was found between sadness and the extent of a person's social contribution, however angry people were perceived more deserving of status and promotion. In Probability theory and Statistics, correlation, (often measured as a correlation coefficient) indicates the strength and direction of a linear Similarly, in the job interviews, angry people were perceived as more suitable for promotion and high salary than sad people.