Like before him the founders of attachment theory, Mary Ainsworth in particular, William Sears teaches that a strong mother-child-attachment emerges from contingency, that is of emotional attunement of mother and child, which again is based on the mother’s sensitivity. Since the mother "reads" the signals of her infant, Sears speaks in this context of "babyreading".[19] Another metaphor that he uses is "to be in the groove".[20]