Vulcan blood is presumed to be green in color , the explanation for this ( first definitely advanced in the installment  Obsession ,  from the original program ) being that the oxiferous ( oxygen-carrying ) protein hemoglobin , in Vulcan blood cells , is chemically based on the element copper , rather than the element iron as is the case with ...
SECONDARY GROUPS The term secondary group has come into use in sociology to describe any group which lacks one or more of the elements that go together to characterize a primary group. In general, a secondary group is composed of individuals who lacks strong emotional ties one another.. (end of quotation) .
Therefore we divided the world into âthemâ and âusâ based through a process of social categorization (i.e. we put people into social groups). This is known as in-group (us) and out-group (them). Social identity theory states that the in-group will discriminate against the out-group to enhance their self-image.The central hypothesis of social identity theory is that group members of an in-group will seek to find negative aspects of an out-group, thus enhancing their self-image.enri Tajfel's greatest contribution to psychology was social identity theory. Social identity is a personâs sense of who they are based on their group membership(s).