Why Do Some Siblings From Troubled Families Turn Out Fine, While Others Flounder?

Tag - You're It!

One nice thing about Google Blogs is that Google provides blog authors like myself with the search terms used in search engines that have led potential readers to find our blogs. 

One recent search term leading a reader to one of my posts struck me.  It was "Five children.  One BPD [borderline personality disorder].  Why?" 

What an excellent question!

Unbelievably, I still occasionally hear the argument that this or that behavioral disorder could not possibly be shaped primarily by dysfunctional relationships with parents, because other children of the offending parents turned out quite different.  That fact proves the disorder is biogenetic?  Of course, in addition to growing up in the same household, siblings also happen to share many of the same genes - but that point is seldom brought up by people who make such claims. 

Anyway, neuroscientists already know for certain that complex behaviors in human beings are not determined by single genes or even by groups of genes.

That siblings turn out different is quite true.  In fact, they can and often do turn out to be polar opposites!  In some families, for example, one son may become a workaholic and the other a lazy freeloader who refuses to keep a job.  I have difficulty imagining a genetic mechanism that would lead to an outcome like that, but it can be easily explained by looking at family dynamics and psychology.

The ridiculous assumption implicit in the sibling argument is that parents treat all of their children the same. 

Do you have siblings?  Do you have more than one child?  Tell me if the siblings are all treated exactly the same by your parents or in your family.  Come on, be honest.



The Smothers Brothers comedy duo in the sixties and seventies made an entire career out of feigned sibling rivalry summed up by Tommy Smother’s catch phrase, “Ma always liked you best.”  Clearly this theme resonated with a lot of people.  Does anybody really treat all of their children in a nearly identical manner?  How could they?  Children are born with major differences from one another that force parents to react differently even if they try not to. 

"Ma always liked you best."

Even more important, anyone who thinks that some parents do not pick out some of their children to treat like Cinderellas and others to treat like princesses has his or her head in the sand. 

In some ethnic groups, contrasting and seemingly unfair treatment of siblings because of their birth order is actually mandated by the culture.  For example, in some Chinese families the oldest son is groomed to inherit the family business, while his younger brother inherits much less if anything.  In many Mexican American families, the oldest daughter has the duty to look after her younger siblings.  She may have to forego her own high school social life in order to do so, while her younger sister has far fewer family obligations and gets to party on. 

Of course, parental behavior is hardly the only influence on how children turn out after they grow up, but it remains one of the most important and potent ones.

Indirect evidence that children are responding to environmental contingincies in the family and not to genetics is also provided by a phenomenon I have occasionally seen that I call sibling substitution. 

I derived this term from a similar term, symptom substitution, which is a subject that was a bone of contention between psychoanalytic therapists - who thought psychological symptoms were caused by an individual’s internal emotional conflicts - and behavior therapists - who thought that symptoms were caused by environmental rewards and punishments impacting certain behaviors. 

The behaviorists claimed that if they just taught patients new and better habits and reinforced them, then they would be completely cured. The analysts said that would not work because the patient’s underlying conflict would still be present, so the patient would therefore develop a new and different symptom.  The behaviorists claimed to have proof that their side won the argument, but that might be because they cured things like phobias that were not caused by internal conflicts in the first place.  Neither side had any evidence for their argument when it came to dysfunctional personality traits.

What I noticed was that if I somehow successfully helped patients to significantly change a dysfunctional role that they were playing within a family of origin, they often did not develop any new dysfunctional behavior, just as the behaviorists would have predicted.  Unfortunately, a previously unaffected brother or sister would suddenly step into the role they vacated!  Hence, no symptom substitution.  Sibling substitution.  While as a patient's therapist I did not owe anything to his or her sibling, I still found this result less than satisfying.  I helped a patient, but in the process I helped screw over his brother!  What good is that?

To illustrate, say that one sibling is the “Chosen One” who has agreed to fulfill a dysfunctional role: He's the one who never gets married so that he remains free to never leave home - in order to keep an eye on an ailing mother after a father runs off.  Let us further suppose that the Chosen One suddenly says to Mom, “I can’t do this any more.  I’m moving out so I can have a life of my own.  You need to find someone your own age to take care of you!” and actually moves out (Mind you, this is something most people playing such a role are highly unlikely to ever do). 

If he follows through, he will usually first suffer universal condemnation from every relative he has.  If that powerful family maneuver does not get him to change his mind, as it usually will, a brother may then move in with Mom and take his place.  The brother may even develop marital problems that lead to a divorce so that he can free himself up to do so.

As an aside, this sequence of events might seem to indicate that all the siblings in such a family had, until this point, been perfectly willing to let one of their number stay in the unhappy position of Chosen One so they could selfishly go off and lead their own lives.  However, selfishness may not be the complete reason they had stayed out of Mom's problems. 

They may pressure the Chosen One to stay in the role, not just to let themselves off the hook, but because they think their mother actually prefers the Chosen One in the role, and wants no one else to play it.  The Chosen One was, in a sense, picked out by Mom specifically to play the role. The Chosen One is treated by the siblings in the way they do for Mom's benefit, not just their own!

So how does it happen that only one sibling among many is chosen to be and volunteers to be (almost always both)  the Chosen One in a situation where a role is not determined culturally by sibling position or gender?  For simplicity’s sake, lets call that person “It,” like in the game of tag. Before I give my opinion on that question, I want to describe a recent journal article that attempted to look at why siblings turn out so different from one another when they allegedly grew up in the same environment.

In an article in the Journal of Personality Disorders entitled, “Psychopathology, Childhood Trauma, and Personality Traits in Patients with Borderline Personality Disorder and Their Sisters,” Lise Laporte, Joel Paris and others studied the sisters of female patients with BPD.  They state in the abstract: "Most sisters showed little evidence of psychopathology [mental problems]. Both groups reported dysfunctional parent-child relationships and a high prevalence of childhood trauma.

Dr. Joel Paris, my colleague in the Association for Research in Personality Disorders

They concluded that the psychological traits of “affective instability” [high reactivity and emotionality] and impulsiveness predicted the degree of borderline pathology over and above the effects of childhood trauma or adversity.  They do not claim that these traits are genetic or inborn exactly, but that seems to be the implication.  Of course, inborn traits do affect the likelihood of the development of borderline personality disorder, but perhaps not in the way that the authors of this study imply.  More on that shortly.

On closer look at the actual numbers, however, a somewhat different picture emerges.  True, only three of 56 sisters in the sample had the disorder themselves, and parental neglect was equally prevalent among the patients and their sisters. However, 76.8% of patients with BPD reported emotional abuse, while only 53.4% of sisters did.  The severity of this type of abuse was also higher for the patients.  Differences in sexual abuse were even more pronounced, with 26.8% of patients and only 8.9% of sisters reporting such abuse.  In this case, however, the severity of the abuse suffered was similar.

As the authors point out, we know that childhood trauma alone does not lead predictably to any specific psychological disorder, but seems to be a risk factor for almost all of them. 

So is resilience in the face of severe family dysfunction primarily genetic?  The short answer is that we do not have the foggiest notion.   In order to really find out, we would have to genotype babies and then do prospective studies lasting all the way through childhood in which the family was filmed twenty-four hours a day – an impossible task.  Maybe the focus of maladaptive parenting was greater on one child than another, and the difference in focus is what leads to the affective instability and impulsivity in the affected sibling – although genes clearly might make one sibling somewhat more prone to these traits than another. 

The authors discount the idea that the dysfunctional parenting was differentially applied  to the sisters in their study, despite the significant differences in some of the numbers.  The sisters, they wrote, reported “equally impaired” relationship with the parents.

But this conclusion may be due to the fact that the important differences in parenting between siblings are far more subtle than studies of this type can possibly measure.  The number of beatings by the father, for example, may be the same for the two girls, but what about everything else that takes place in the father's separate relationships with the two daughters?  Was the father nicer to one than the other at those times when he was not being abusive?  What was said to each girl during the beatings?  I find that details such as these are of crucial importance in understanding patients with BPD.

As I said in my blogpost of Sept 15, Childhood Sexual Abuse Taken Out of Context: “Studies that examine psychological and social variables in child sexual abuse (CSA) tend to focus on factors such as who the perpetrator was, what type of abuse was suffered (penetration vs. fondling, for example), the severity and frequency of the abuse, and whether the social welfare or criminal justice system became involved. Rarely, the response of non-abusive relatives to CSA victims, usually the mother, is examined. ..

Clearly, most of the victim’s interactions with perpetrators and bystanders alike occur at times when abuse is not occurring, and these other parts of such relationships may also have profound effects on the victim’s later relationships and self image. Again, due to their staggering complexity and intermittent nature, they are difficult to study using statistical techniques.

Contextual factors include the entire history of the relationship between the victim and the perpetrator: what is said during, before, and after the abuse; what the relationship between victim and perpetrators is like when the abuse is not taking place; what other people in the family are doing at the time of the abuse and at other times; how each family member relates to the victim; who if anybody knows what is going on and whether or not they intervene; and a whole host of other characteristics of the interpersonal environment of the victim.

Even during abuse, a victim’s interactions with a perpetrator is not limited to the sex act alone. Words may be spoken; other activities may occur right before, right after, and even simultaneously.”  

These considerations are, while of vital importance, are almost impossible to quantify.

“So get to the question of why one child is singled out already,” I hear you complaining.  “Why would parents focus their conflictual behavior on one or perhaps two of their children, leaving the others relatively unscathed?"  OK, OK, I'll tell you why I think that happens. 

In families with several children, which child or children become the primary focus of the parents’ conflicts and problems depends on a variety of factors.  Certainly a child’s innate temperament plays a role, so we cannot leave genetics completely out of the equation.  A parent who really does not fully want to be a parent but who feels guilty about this impulse (something commonly seen in families that produce a child with BPD), will react more problematically to an innately difficult child than to an easy child.  The latter simply requires a lot less attention, while the former requires much more time. 

Additionally, the problems exhibited by a difficult child may feed into a parent’s guilt over wishes to be free of family burdens.  The parents may become concerned that perhaps their unacknowledged dislike for taking care of children is the cause of the child’s problems.  Hence, parents who are already feeling overburdened yet guilty will often feel guiltier with difficult children.  In response, they often try to overcompensate by getting more involved with those children, which may then further increase their resentment over the parenting role.  The difficult temperament of the child and the internal conflict of the parents feed off of one another, leading to more family conflict and chaos, and so forth.

I will describe how the parents may develop such an internal conflict in my next post. 

Another major factor which determines which child or children become “It” has to do with the natural similarities between particular children and the parents themselves, or between the children and other family members with whom the parents may have had a conflictual or problematic relationship.  Parents are well known to both identify and counter-identify with their own children. 

Say, for example, the mother is the oldest sister in a traditional Chicano family and had been required to give up her social life or college as a young woman in order to take care of her younger siblings.  She then grows up and has children of her own, thrusting her back into the exact same, conflictual position. Because of identification, she might feel sorry for her oldest daughter and envious of her youngest daughter.  Conversely, depending on the extent and severity of her resentment and her conflict over it, she might be harshest on the eldest daughter, who reminds her most of herself.

Either way, the manner in which she interacts with each daughter will be completely different. 

In a similar fashion, light skinned vs. dark skinned children in black families may be the seed of subconscious differential treatment by parents.

Yet another major factor in one child becoming “It” is that parents may often subconsciously displace conflicted feelings about their own parents or other family members on to children who have a physical resemblance or a similar innate personality to the problem parent. That child may then become the focus of the parent’s anger, guilt, or a variety of other problematic feelings, thereby creating a special bond (be it positive or negative) with that particular child and not with any of the others.

Because of the multiplicity of factors involved, determining the exact reasons why one child is the primary focus in any particular family is a speculative and difficult endeavor.  Luckily, in psychotherapy an absolutely accurate and precise identification of these factors is not necessary for planning strategies for altering dysfunctional interactions.  An educated guess will usually suffice.