Babies and toddlers

Harmful conflict can Interrupt foetal physical and mental development and there can be longer term effects through foetal programming (epigenetics)⁵. Babies may have a lower birth weight, arrive prematurely, and have difficulty sleeping²³. There can be a higher incidence of autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD).⁵

Children as young as six months can show distress such as an increased heart rate in response to hostile parental exchanges¹. Children up to the age of five years show distress by crying, acting out, freezing or withdrawing from conflict⁷. Younger children are more likely to show distress in response to overtly hostile (parents shouting and openly angry behaviours) conflict.^11,33

Physically, children’s growth can be affected and they might complain of tummy aches, headaches and tiredness.³⁰

Boys

Children who perceive conflict as threatening or who feel unable to cope may experience more externalising type problems (aggression, behaviour problems).^9,10 Children who blame themselves for parental disagreements may experience more internalising type problems (anxiety, depression)^18,19,20; boys are more likely to interpret co-parental conflict as a threat to themselves and thus externalise their feelings²².

Boys’ responses will also vary by age and developmental understanding. Younger boys are more likely to display their distress in response to openly hostile parental conflict (parents shouting, slamming of doors, name calling, etc.), while older boys will be able to notice more covert conflict (withdrawal by one parent, the silent treatment, refusing to attend the same school event, etc). Academically, boys may struggle;⁴ this may be about a lack of sleep, affecting brain development (especially in the first 18 months of life),²⁶ or poor school adjustment and friendships, having learned to expect negative relationships from the example their parents have given (modelling)⁵³

Physically, boys may struggle with tiredness, headaches or abdominal issues ^28,29,30. They are also likely to struggle with the social skills needed to maintain friendships (for example the ability to empathise or problem solve).^39,40,41,42

Girls

Children who perceive conflict as threatening or who feel unable to cope may experience more externalising type problems (aggression, behaviour problems)^14,17,22. Children who blame themselves for parental disagreements may experience more internalising type problems (anxiety, depression)^18,19,20,21.

Girls are more likely to perceive co-parental conflict as a threat to the harmony of the family, feel caught in the middle and feel the need to intervene, taking on unhealthy roles as ‘mediators’ or providing ’emotional support’ for parents and siblings.^22,46,47,48

Girls’ responses will also vary by age and developmental understanding. Younger girls are more likely to display their distress in response to openly hostile parental conflict ( parents shouting, slamming of doors, name calling, etc.)³³, while older girls will be able to notice more covert conflict (withdrawal by one parent, the silent treatment, refusing to attend the same school event, etc). Academically, girls may struggle;⁴ this may be about a lack of sleep, affecting brain development (especially in the first 18 months of life),²⁶ or poor school adjustment and friendships, having learned to expect negative relationships from the example their parents have given (modelling)⁵³

Physically, girls may struggle with tiredness, headaches or abdominal issues ^7,27-29. They are also likely to struggle with the social skills needed to maintain friendships (for example the ability to empathise or problem solve).^39-42

Teenagers

Older children are more likely to have a ‘real understanding’ of the conflict between co-parents, increasing their desire to comment, intervene or take on the burden of the conflict. Longer exposure to conflict may have also affected them more negatively.⁴⁵ Hormonal changes and the effects on the developing brain make this a dangerous time for emotional outbursts, their own relationship skills and longer- term mental health conditions.¹⁵ The conflict may also impact on more risky behaviours in teenagers, including smoking, substance abuse and early sexual activity^34-38

The teenage brain