Family Dysfunction and Gene Expression: Effects on Personality and Behavior

Jenny Macfie, Ph.D., Department of Psychology, University of Tennessee Knoxville

It’s amazing what you can discover if you actually look

When it comes to the “scientific” literature about what causes borderline personality disorder (BPD) and other forms of self-destructive and self-defeating behavior, readers of my blogs know that I think genetic influences are way overemphasized and the effects of dysfunctional family dynamics and child abuse ignored as much as possible.

In my clinical practice, I see dramatic evidence that the effects of the family dysfunction on behavior are often passed down from one generation to the next.  A few studies have also looked at this, and in every case supported this viewpoint.

Two more recent studies support my views in general about what creates the disorder.

Jenny Macfie and others, following the work of Karlen Lyons-Ruth described in a previous post, actually watched the interactions between children aged 4-7 and their mothers with BPD (“A Mother’s Borderline Personality Disorder and Her Sensitivity, Autonomy Support, Hostility, Fearful/disoriented Behavior, and Role Reversal with her Young Child,” Journal of Personality Disorders 31(6):  pp. 721-737, 2017).  

The pairs were given a task with the following instructions: “This puzzle is for your child to complete, but feel free to give any help your child might need.” A researcher presented one puzzle at a time in order of increasing difficulty.  Mothers who did not have the disorder and their child were also given the task. All interactions were observed and scored.

Mothers who had BPD “demonstrated significantly less sensitivity and autonomy support [supporting the child’s efforts to solve the puzzles without the assistance of the parent], more hostility, more role reversal, and more fearful/disoriented behavior in interactions with their children than did comparison mothers.

“Role reversal” is the child taking care of the mother instead of the other way around. In this study they specifically looked at mothers deferring to their child’s demands, the pair acting like playmates (for example, child abandons task and the two run around the room rather than the mother setting limits), and mothers taking the child’s attention away from the task by demanding signs of affection from the child.

There was no group of mothers with other personality disorders so we do not know if the researchers results are specific to mothers with BPD.

In a second, unrelated study, Pierre Eric-Lutz and his colleagues looked at the effects of child abuse on the expression of genes that control the development of the brain (“Association of a History of Child Abuse with Impaired Myelination in the Anterior Cingulate Cortex: Convergent Epigenetic, Transcriptional, and Morphological Evidence,” American Journal of Psychiatry 174 (12), pp.1185-1194, 2017).

Epigenetics refers to the process by which environmental influences turn genes on and off. Most genes in a cell are not operating at all at any given time. Epigenetics ties environmental and genetic influences together in ways that a lot of people in the various mental health field either seem to be unaware of, or consciously ignore. The anterior cingulate cortex is a part of the brain heavily involved in making decisions regarding what to do in various social situations.

Without going into the authors’ methodology, which was quite sophisticated, the study found that individuals abused during childhood showed significantly decreased expression of a large collection of genes involved in myelination of cells in that part of the brain. Myelination is process which markedly changes the level of functioning of brain cells that are part of so-called white matter.

Once again, we find that one of the main purposes of the genes that create the brain in human beings is to make humans exquisitely sensitive to the social environment.

Genetic Programming Makes Nurture the Most Important Factor in our Behavior: Another Paradox

Claudia Gold, on a post on her Child in Mind blog, mentioned in passing that 700 new connections per second are made in the brains of newborns within the context of caregiving relationships. 700 per second! 

One of the basic theories behind my psychotherapy treatment method (unified therapy) for repetitive self destructive or self-defeating behavior patterns is that the behavior of primary attachment figures - in most cases, the parents - are, from a cognitive-behavioral standpoint, simply the most important environmental factor in triggering and reinforcing the problematic patterns. And not only when we our children, but throughout life. Certainly more powerful than a therapist could ever be.

I argue that babies come into the world completely helpless and with absolutely no knowledge about how the universe operates. We remain helpless far longer than the young of most species. Therefore, evolution likely proceeded in a way that resulted in our being biologically programmed to wire our automatic and repetitive  behavioral responses in most environmental contests - in particular social contexts - in accordance with what we learn from our interactions with those attachment figures. 

There is much evidence from neuroscience that the brain wiring that develops in this context and remains in the brain is particularly resistant to change through the normal process of neural plasticity. While it is true that later in childhood and adolescence the number of these connections is greatly reduced through a process called pruning, I suspect the ones that are lost are those that are not continually reinforced by the attachment figures.

In the nature-nurture debate about psychological behavior problems, for most of them I come down on the side of nurture being far more important than nature. Nature just provides us with a range of possible behaviors and reactions, while both nurture (and thinking - don't forget about that) allow us to choose where in that range we would prefer to reside.

But our nature as determined by our genes apparently does have one all-important function. Interestingly, it is the same influence no matter what the rest of our individual genome (assuming we have intact neural functioning) contains: it dictates that we are highly likely to respond to our nurture in accordance with the feedback provided to us by our parents. Paradoxically, it is nature that makes nurture so damned important in determining our behavior.

So learning about those 700 connections per second seemed to me to be good evidence for this point of view. So I looked up the source and found an article published by  Harvard's Center on the Developing Child. It said that those neural connections "...are formed through the interaction of genes and a baby’s environment and experiences, especially “serve and return” interaction with adults, or what developmental researchers call contingent reciprocity. These are the connections that build brain architecture – the foundation upon which all later learning, behavior, and health depend."

Serve and return was further explained as interactions that shape brain architecture: "When an infant or young child babbles, gestures, or cries, and an adult responds appropriately with eye contact, words, or a hug, neural connections are built and strengthened in the child’s brain that support the development of communication and social skills. Much like a lively game of tennis, volleyball, or Ping-Pong, this back-and-forth is both fun and capacity-building. When caregivers are sensitive and responsive to a young child’s signals and needs, they provide an environment rich in serve and return experiences."