Define the psychological disorder referred to as loneliness,and describe the two main types outlined in the text.

Loneliness is defined as the sad yearning for intimacy that results from perceived deficiencies in the number and quality of friendships.There are two types of loneliness: social and emotional.The intensity of social loneliness is related to the degree of discrepancy between one's desired number of friends and one's actual number of friends.How much emotional loneliness one feels is determined by the discrepancy between one's desired level of intimacy and one's actual level of intimacy.