The author maintains that the modern psychoanalytic technique of joining to resolve resistances to progressive emotional communication can be understood with reference to attachment theory as stimulating the wish for secure attachment, which is seen as a critical maturational need. Here, the author presents a case example that illustrates how successful joining simultaneously resolves resistance-conceptualized as a symptom of insecure attachment—and arouses attachment dynamics. Aspects of attachment theory and motivation theory are reviewed to suggest that joining techniques in group treatment are especially effective when attachment-related intrapsychic conflicts are stimulated and worked through within the transference.