Some psychologists have claimed that there are three fundamental human emotions: fear, joy, and anger. Neil Smelser, John , and others have proposed three corresponding forms of the crowd: the panic (an expression of fear), the craze (an expression of joy), and the hostile outburst (an expression of anger). Each of the three emotions can characterize either a "compact" or a "diffuse" crowd, the result being a scheme of six types of crowds. Lofland has offered the most explicit discussion of these types.