Communication
The inability of David, Harriet, Ozzie, and Rick to communicate with each other is one of the play's central themes. The most obvious communication problem is between David and the rest of the family. When David returns from Vietnam, the family tries to communicate with him the same way they did before he left. This does not work because David has been profoundly changed and had experiences that they find distasteful (i.e., involvement with the Asian Girl). At the same time, David does not want to communicate with them on their terms and can only express his angry feelings toward them in destructive ways. This standoff ends when Rick, Ozzie, and Harriet convince David to commit suicide and help him complete the act. There are communication issues in the play between the other members of the family. Superficial conversations are what makes everyone but David most comfortable. Ozzie and Harriet do not communicate well with each other. Ozzie tries to talk with his family about his lost youth, frustrations, and problems, but no one really listens. Rick is primarily concerned with himself. He does not listen to his parents' real concerns, only his own needs. But when David's continued presence starts interfering too deeply with the cozy life the family has constructed, it is Rick who makes the first move toward making him go. Instead of solving the problem through improved communications, the problem (David) is eliminated.

Alienation
One concept that also plays a significant role in Sticks and Bones is alienation. David is both estranged and alienated from his family. From the moment he enters his family's home, David wants to leave. The suburban life they lead is now alien to him because of his experiences in Vietnam. He cannot relate to his home or the people who live in it. At one point, he tells both his brother and father how much he hates them. This hostile barrier grows because of the family's communication problems and their racist attitude towards the only person David holds dear, the Asian Girl. David's alienation increases and the hostile barrier becomes larger throughout the course of the play. One way David shows his alienation is by spending much of his time in his room. When there is an uncomfortable scene in the living room, David goes there. He becomes violent with both his mother and Father Donald when they invade it. David's alienation throws his family's ordered life into disarray, contributing to their decision to get rid of him. David is not the only character who suffers from alienation. Ozzie is also alienated from the family on some level. Like David, he tells both Rick and Harriet at different points how much he hates them.

Racism and Disgrace
One secondary theme in the play is related to racism. Harriet and Ozzie are disgusted by the fact that David was involved with Asian women, particularly the Asian Girl, while in Vietnam. They believe that this relationship was disgraceful and brings dishonor to the family. They cannot accept it on any level. Both Ozzie and Harriet often refer to the Asian Girl and her race as "yellow." They, as well as Father Donald, call the Asian Girl a “yellow whore" and believe she had to be diseased. The couple work themselves up over the possibility that they could have had "chinky" grandchildren. At one point, Harriet tells Ozzie that the Bible says something negative about Asians. But when Ozzie goes off on the subject, Harriet reminds him that they are all God's children, the only moment someone other than David defends the Asian Girl.