Intimacy vs. Isolation is the stage of the young adult (ages 20 to mid-30's), according to Erikson's "Eight Ages of Man." During this stage, we are eager to fuse our identities (solidified in the previous stage—Identity vs. Role Confusion) with others. On the other hand, those unsure of their identities may avoid this fusion.
If everything goes well, he or she will reach "true intimacy." If something hinders this progress (e.g., incest), that person may isolate him- or herself from closeness with others. The difference between "intimacy" and "intimacies" is also explored.