The findings of the study were published in the journal 'Personal Relationships'.
Abusive intimate relationships are sometimes characterised by a power imbalance, with the abuser maintaining control over the abused party by limiting their financial, social and other choices.
This is known as coercive control, or battery when severe physical abuse is involved. But what happens when the abuser uses the couple's children as a weapon of control?
This particular situation has a name -- parental alienating behaviours -- and Colorado State University social psychologist Jennifer Harman has devoted much of her career to bringing awareness to the issue via scientific inquiry.
Parental alienating behaviours are those in which a parent tries to baselessly turn a child against the other parent, usually during a divorce or separation, through actions like bad-mouthing, lying, guilting or rewarding.
Such behaviours result in parental alienation, in which a child turns against a parent for unjust or untrue reasons.
Harman and colleagues note that it is important to distinguish alienation from estrangement, which is when the child severs ties with the parent for legitimate reasons like abuse or abandonment.
Alienation occurs when the child severs ties with a parent who is fit to parent but has been painted falsely otherwise.
A new study by Harman, an associate professor at CSU, and colleagues is the first to apply longstanding interdependence theory to the power dynamics in families affected by parental alienation.
Interdependence theory is an approach to categorising interpersonal relationships, focusing on how each person's outcomes depend on the actions of others.
It defines how and why people make certain choices within relationships, and how dependencies on others can create power imbalances in relationships.
Asymmetries of power
The study, co-authored by Harman's graduate student, Caitlyn Grubb, and University of Illinois researcher Christopher Maniotes, was based on detailed interviews with 50 fathers and 29 mothers who had been alienated from their children.
Most of these families exhibited asymmetries in power between the parents, underscoring the argument that parental alienation and coercively controlling abuse are similar -- two sides of the same coin, Harman said, and they should be treated similarly in family court proceedings.
"Our findings show that parental alienating behaviours more closely resemble coercively controlling violence, intimate terrorism and battery than other more common types of abuse, such as situational couple violence," Harman said.
"Parental alienating behaviours are abusive and should be included under legislation and policies that seek to protect children," Harman added.
Imbalances of power are created by alienating parents who employ controlling strategies like harassment, threats and intimidation.
The resulting climate disempowers the other parent by making them feel their behavioural options are limited, fearing they will lose their children or become hurt themselves.
About 80 per cent of the situations studied involved asymmetries of power, some of which could be described as games of "chicken" -- providing only two, narrow choices to the parent with less power, perpetrated by the alienating parent in order to gain or maintain control of the parenting dynamic.
The researchers also found that such asymmetries were most prevalent when the perpetrating parent had primary or sole custody of the children.
Harman and her colleagues' work also shows that parental alienation is mostly gender-neutral; both fathers and mothers do it at about the same rates, although they use different tactics.
This gender neutrality matches national statistics on other abusive behaviours like stalking, physical and sexual abuse.
"We don't see gender differences in many other types of abusers," Harman said.
How children suffer
While parental alienation is essentially partner abuse, the children suffer, too, Harman said.
In a recently published review paper, she discussed the losses alienated children endure, including childhood experiences, extended family, community, activities and relationships.
Over the span of several years of research on the topic, Harman has fielded mountains of criticism from those who believe parental alienation is an excuse used by abusive parents in order to dodge child abuse allegations.
A paper she and co-author Demosthenes Lorandos, an attorney and forensic psychologist, published earlier this year rebutted those claims.
Harman plans to continue publishing research that brings credibility and awareness to the problems parental alienation causes for families, children and society at large.