Mercer, like Bowen, focuses upon potentially negative social forces that could potentially impact the critical relationship at the heart of the theory. But once again, these potential negatives are rooted to some extent in biological as well as social and psychological factors. "Young maternal age and immaturity, socioeconomic status" are all potential red flags particularly since they have been shown to reduce the likelihood that the mother will breastfeed and 'bond' with the child in a meaningful fashion (Husmillo 2013: 47). A lack of appropriate mother-child bonding is seen as having significant psychological consequences for the baby over the course of its existence, as well as the fact that a failure to breastfeed and to reinforce trust and security for the child can result in compromised long-term health and a failure to thrive. Mercer's theory is thus aimed to support a particular type of wellness promotion for the children involved. However, the theory can be differentiated for to allow for women's varied experiences of becoming mothers, including the type of birth they have (natural vs. C-section); having children who are born with birth defects, and other issues (Husmillo 2013: 47). This differentiation is strongly grounded in Mercer's sense of evidence-based practice, which clearly marks her theory as explicitly as a 'nursing' theory, versus Bowden's more abstract theoretical concept of family relationship triangulation. For example, to support her theory, Mercer notes: "findings suggest a strong correlation between the development of postpartum depression and a decrease in the mother's emotional bond to her infant. Negative impact on the maternal-infant bond was evident when maternal depressive symptoms were present two to three months postpartum" (Husmillo 2013: 47-48). Bowden views a lack of positive independence between family members as potentially damaging, but Mercer's specific, targeted focus on the mother-child relationship leads her to see a lack of interdependence as producing neurosis and alienation, not emotional enmeshment as in Bowden.

Mercer's nursing focus is also evidenced in the more physical component of her theory, reflecting her orientation as a nurse. Giving birth and nursing is a biological, not a purely psychological process and certain physiological conditions (such as touching) are necessary for the bond to take place. Other physiological conditions can potentially thwart the mother's physical attempt to bond with the child, such as an overly impersonal hospital environment or the mother's uncertainty about how to care for the infant and her withdrawal. Bowden's theory lacks this physiological, hands-on component.

A final, but significant component of Mercer's theory is her conception of nursing and definition of nursing, which is also clearly not present in Bowden's theory. Mercer sees the nurse as an educator. "Nurses and childbirth educators should model good behavior during each and every interaction with the patient while simultaneously providing valuable patient teaching in a sincere manner and in small amounts" (Husmillo 2013: 47-49). In Bowden, the therapist acts as a facilitator and offers objective guidance and analysis and is not an involved participant in the process of negotiating new family relationships as a 'role model.'

Application

Both Bowen and Mercer's theories, it could be argued, arose because of the increasing...

Not only does this individualism eliminate a very important component of human life, it could also be argued that this is ideologically problematic, given that many cultures do not stress individualism to the same extent as the United States. Both theories are very much products of their own times and cultures. Bowen views independence as an ideal, while Mercer insists upon an extremely intermeshed relationship between mother and child in a manner that demands a very specific type of modern 'attachment' mothering that might not resonate with women of all cultures and classes. However, although a nurse must be careful when applying these theories and view them in terms of the needs of the client, recognizing that not all clients have cultures which have the same conceptualization of family, there is a similarity of roles in both theoretical overviews that can be useful to the nurse. Mercer (2004) herself cautions that a multitude of factors can influence maternal role perception and role attainment and Bowen does not apply a 'one size fits all' approach to families (Mercer 2004:227).
In both theoretical overviews, "the nurse functions as a teacher, consultant, and a role model" (Knauth 2003:331). Bowen's theory will likely have a wider application because it deals with relationships beyond the mother-child dyad, although the nurse must be careful not to view a culture where longstanding extended family relationships are very close is 'normal' as inherently pathological. But a nurse does not necessarily need to be culturally relativistic, either when applying Bowen's concepts: she must ask if the relationships are health-promoting or stifling the physical and psychological health of the clients. Bowden believed that "emotional distance, marital conflict, dysfunction in a spouse, and impairment of one or more children" are universal problems and universally lead to "physical illness, emotional illness, and social illness, and the less [one] is able to consciously control [one's] own life" but the nurse has considerable leeway and discretion in defining how these conditions are pathological for the family (Knauth 2003:335-337). It is Mercer's emphasis on breast-feeding and mother-child touching that is somewhat less flexible and must therefore be applied with great caution -- even if certain health practices are generally deemed superior within the theory and by empirical medicine, every patient's circumstances are different and the nurse must support the mother in determining the best choices for both her and her baby.