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Birth Order and Eating Disorders

Kristen Thomas

I. Introduction:

Individuals are pieces of a whole, called the family. The family has an undeniable influential role on each of the members of the unit, and conversely the individuals’ influence on the family unit. With this undeniable understanding of the family, it is important to look at the relationship between those with eating disorders and birth order. Is there a correlation between birth order and the development of either anorexia nervosa or bulimia? However, birth order only scratches the surface of the relationship between eating disorders and the family unit. Looking past potential relationships between birth order and eating disorders, is there the possibility of a relationship between eating disorders and the family dynamic? Perhaps the dynamic of the shared relationship between family members, beyond sibling relationships, plays an important role in the development of either anorexia nervosa or bulimia.


II. Birth order effect?

Locating studies with a focus on a relationship between birth order and eating disorders is a difficult task. Little research has been conducted to look for possible correlations between rank in birth order and the development of either anorexia nervosa or bulimia. Few researchers have attempted to look for a correlation, and those that have completed studies have conflicting findings.

Rowland (1970) searched for a relationship between birth order and anorexia nervosa. In his study, he found that those with anorexia nervosa were overwhelmingly the eldest children; however, his study just fell short of statistical significance. Crisp (1977) and Crisp et al. (1980) tried to duplicate his findings but failed to support Rowland. On the contrary, the two studies found an excess of later born siblings and the development of eating disorders. Findings for birth rank and anorexia have thus far proven to be inconsistent and more studies need to be conducted to determine the relevance of birth rank and anorexia.

Similarly, few studies conducted have focused on birth order and bulimia. Ebert (1983) and Dolan et al. (1989) failed to find any significant deviation from expectation in the birth order of patients with bulimia. Lacey, Gowers and Bhat (1991) found that in small families, the bulimic was more likely to be the only or oldest child, however this held no statistical evidence. The second finding in the study is that bulimia is represented in all family sizes, but of particular interest is that all-female siblingships were well represented, but this too did not prove to be statistically significant. There is little agreement whether birth order or the sex composition of the siblingships had any relationship to eating disorders. Again, more studies need to be conducted to come to any conclusions between birth order and bulimia.

Studies that examine birth order are vulnerable to a number of biases that are not immediately apparent. Such studies examining birth rank require the participants to self-report. When an individual reports information, there is the possibility for the individual to conceal a true birth order effect. This is because they may fail to report older siblings that have deceased, particularly siblings they have not known and those that were still born or miscarried. The death of an older sibling that one has not met may not be significant, particularly because it is the participants’ experience of family life from the point of their self-perceived rank in the siblingship is most important (Britto, 1997).

These biases are important to keep in consideration, however they are not so great as to skew the results. Unfortunately, the results still do not prove to be significant. The number of published studies of birth rank in eating disorders may be too small to detect any significant effect. Perhaps, while there is no statistical relationship for eating disorders and birth order, one should look at the relationship of the family as a whole entity.


III. Environmental family factors:

While examining one facet of the family relationship produced little evidence for a relationship for eating disorders; perhaps the family as a whole entity should be examined to look for clues. Conceivably the family dynamic plays a larger role for the development of eating disorders, if environmental factors are even significant.

Examining families with a member diagnosed as anorexic, it is revealed that the organization of the family is quite rigid. Minuchin is a family systems theorist that has examined the relationship of families with individuals diagnosed with anorexia. He has found four key factors that are characteristic of the "anorexic family". First is ‘Enmeshment’; the family members view themselves more as an entity rather than individual that makes up a whole. Second is ‘Overprotectedness’; parents are more controlling and do not let their children to explore the world openly. Third is ‘Rigidity’ or an unwillingness to change the dynamics of the family. Finally is ‘Avoidance’, particularly of open discussions of parent-child conflict. (Scott, 1988). Also according to Minuchin, "certain kinds of family environments encourage passive methods of defiance and make it difficult for members to assert their individuality" (Brumberg, 1988, p. 29) and consequently the family is afflicted with the disease. Conversely, family serves as a perpetuating factor of anorexia.

Researchers have found that the structure of the bulimic family is remarkably different from that of the anorexic family. Those diagnosed as bulimic view their families as conflicted, poorly organized and lacking in nurturance and caring; and parents place more contradictory demands on children. Also in contrast to the anorexic family, the bulimic family has stronger boundaries between family members and do not avoid conflict (Brownell, 1995). Looking beyond characteristics of the family entity and to the characteristics of the individuals comprising the unit, one finds significant parental factors. Herzog (1984) found a significant number of alcoholic family members and family members struggling with weight problems in the immediate family of those diagnosed with bulimia. Specific family members outside of siblings also have been examined as to whether they have had a negative impact bulimics and it has been found that mothers have a higher incidence of depression compared to non-bulimics. Fathers of bulimics were found to be more impulsive than fathers of non-bulimics. Characteristics of individuals of a family unit as well as the characteristic of the family unit have proven to have a greater influence on bulimics than birth order.


IV. Conclusion:

Studies investigating the relationship between birth order and eating disorders have been to few to detect any genuine effect. Statistically relevant information has not come out of these studies; more studies need to be conducted to come to a purposeful conclusion concerning birth order and eating disorders. As it currently stands, birth order does not have any direct impact on the relationship of eating disorders.

However, delving further into the family and the families’ dynamics, it is evident that family members play a significant role in the development of eating disorders. Not only do certain family members impact those diagnosed with an eating disorder, but also the characteristics of the family unit directly impact the individual. With this knowledge, one could further their query into family theories of causation, and review sibling relationships as well as ask if genetics plays a predominant role in developing eating disorders.


V. Bibliography:

Britto, D.J. et al. (1997). Anorexia nervosa and bulimia nervosa: Sibling sex ratio

and birth rank- A catchment area study. International Journal of Eating Disorders, 21 (4), 335-340.

Brownell, K.D., & Fairburn, C.G. (Eds.).(1995). Eating disorders and obesity: A

comprehensive handbook. New York: The Guilfod Press.

Brumberg, J.J. (1988). Fasting girls. Cambridge, Mass: Harvard University Press.

Dolan, B.M. et al. (1989). Family composition and social class in bulimia: A

catchment area study of a clinical and comparison group. Journal of

Nervous and Mental Disease,177, 267-272.

Gowers, S., Kadambari, S.R., and Crisp, A.H. (1985). Family structure and birth

order of patients with anorexia nervosa. Journal of Psychiatric Research, 19 (2-3), 247-251.

Herzog, D. (1984). Are anorexics and bulimics depressed? American Journal of

Psychiatry, 141, 21-24.

Lacey, J.H., Gowers, S.G., and Bhat, A.V. (1991). Bulimia nervosa: Family size,

sibling sex and birth order- A catchment area study. British Journal of

Psychiatry, 159, 290-291.

Rowland, C.V. (1970). Anorexia nervosa. International Psychiatric Clinics, 7, 37-


Scott, D. (Ed.).(1988). Anorexia and bulimia nervosa: Practical approaches. New

York: New York University Press.


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