Taken from www.papaorg.co.uk Link to full article at the bottom.

When one parent turns a child against the other, the child’s brain undergoes complex changes to cope with the emotional conflict. 
This adaptation often leads to the child pushing the targeted parent away, leaving many adults confused and hurt.   
Understanding how a child’s brain responds to parental alienation can shed light on why children behave this way and how healing can begin.
 
This article explains how parental alienation affects a child’s developing brain, leading them to reject a parent as a coping mechanism, and highlights ways to support healing and reconnection.

How Parental Alienation Affects a Child’s Brain
Children rely heavily on their parents for emotional security and guidance. 
When parental alienation occurs, the child faces conflicting loyalties and emotional stress.  
The brain reacts to this stress by adapting in ways that can affect behaviour and emotional responses.
 
The Role of the Developing Brain
The brain of a child is still developing, especially areas responsible for emotional regulation, decision-making, and social relationships. 
The prefrontal cortex, which manages reasoning and impulse control, is not fully mature. 
Meanwhile, the amygdala, which processes emotions like fear and anxiety, is highly active.  
When a child experiences alienation, the amygdala can become overactive, leading to heightened emotional responses.

Emotional Conflict and Cognitive Dissonance
Parental alienation creates a situation where the child receives mixed messages: love and loyalty toward both parents, but pressure to reject one. 
This conflict causes cognitive dissonance, a mental discomfort from holding contradictory beliefs. 
To reduce this discomfort, the child’s brain may unconsciously choose to align with the alienating parent, pushing the other away to restore emotional balance.
  
Impact on Attachment Systems
Attachment theory explains how children form emotional bonds with caregivers. 
Parental alienation disrupts this bond with the targeted parent. 
The child’s brain may suppress feelings toward that parent to avoid emotional pain. 
This suppression can look like rejection or indifference, but it is often a protective mechanism. 

Why Children Push Away the Targeted Parent
It can be heartbreaking when a child distances themselves from a loving parent. 
Understanding the brain’s role helps explain this behaviour.

Survival Mechanism
Children want to feel safe. 
When one parent speaks negatively about the other, the child may feel that rejecting the targeted parent is necessary for safety and acceptance.
The brain prioritises emotional survival over truth or fairness.
 
Learned Behaviour and Repetition
Children learn from their environment. 
If the alienating parent consistently portrays the other parent as harmful or untrustworthy, the child’s brain internalises this narrative. 
Over time, this becomes a default belief, making it difficult for the child to reconnect without intervention.

Emotional Exhaustion
The constant pressure to choose sides can exhaust a child emotionally. 
To cope, the brain may shut down feelings toward the targeted parent, creating emotional distance as a form of self-protection.
  
Signs That a Child’s Brain Is Struggling with Parental Alienation
Recognising how a child is affected can help adults respond with empathy and support.
Sudden rejection of one parent without clear reason 
Inconsistent emotions, such as anger or sadness toward the targeted parent 
Difficulty trusting adults or forming new relationships 
Withdrawal or isolation from family members 
Changes in behaviour, including anxiety, depression, or aggression 

These signs indicate that the child’s brain is under stress and adapting to a difficult emotional environment.

Full article through the link below:
https://www.papaorg.co.uk/post/how-a-child-s-brain-adapts-to-parental-alienation-and-why-they-push-you-away