when one person is compelled to think or imagine the response of other person or persons he is said to be in 'tension'.The mental slot of two persons are not the same.We imagine the other person's response by using our own mental slot.We evaluate the other person from his responses or reactions. As for eg: the no.4 can be derived from diffrnt combinations,2+2=4, 3+1=4, 0+4=4,5-1=4........the same response or reactions are the products of diffrnt types of mental combinations in diffrnt persons.Thus to avoid tension we want to put our legs in our own shoe. Try to understand other persons through their own life conditions.