Humans are sensitive to others’ possessions, such as talents, appearance, achievements, etc. By comparing ourselves to others, we assess self-evaluation and personal satisfaction. Here, reviewing recent neuroscientific findings, we will illustrate the neural mechanisms of emotional reactions to the perceived inequity of social comparison by both the level of contextual appraisal and the automatic level of perceiving the emotions of others. Envy, schadenfreude, empathy and counter-empathy are predominant emotions associated with social comparison, and the brain is predisposed to generating them according to others’ conditions. It is argued that happiness is not just a pure hedonic state but is a matter of others, whose happiness cannot exceed ones own.