As parents we try not to row in front of our children. Instinctively, we know they find it hard to cope when we're at odds with one another, and they're disturbed if our arguments become persistent or hostile. This is plain common sense.But there's some important new information that all parents need to be aware of. It was published in a new report by the Early Intervention Foundation, where I am CE, along with the University of Sussex.Its findings? Simply: that unresolved conflict between parents has a potent influence on children's early development.This is true whether the parents are together or apart.Having disagreements is normal, of course. What does the harm is the "unresolved" part. Children need to know that arguments can be settled, allowing life to move on.Ongoing conflict between parents can affect children's mental health, the development of their social and emotional skills, academic attainment - and can affect their ability to form relationships.It can also damage their physical health, lasting through their adult lives and into the next generation. And it starts early.Babies as young as six months show higher physiological symptoms of distress, such as an elevated heart rate, in response to overt exchanges between parents.But children of all ages can be affected by destructive inter-parental conflict outwardly through high levels of aggression, hostility and violence, and inwardly through low self-esteem, anxiety, depression and, in extreme cases, suicidal feelings.Much of the focus of early intervention has been on the relationship between the parents - usually the mother and child. But this report suggests that it's actually the quality of the inter-parental relationship that has a significant influence on children's long-term psychological outcomes and the quality of parenting they receive.It's a critical missing piece of the jigsaw.We may kid ourselves that our children don't notice rows, but the reality is they're highly perceptive and attuned to how their parents relate to each other.How children perceive their parents' level of conflict determines how they expect their parents to behave towards them and this, in turn, can lead to psychological distress.What's fascinating is that conflict between parents has more of an impact on the relationship between a father and child than a mother.As a dad, if you're having frequent difficulties in your relationship, this is more likely to filter into how you relate to and parent your offspring.Mums seem to be better at insulating their children from this spill-over effect.This dynamic is important for thinking about the best ways of supporting families and children to address these issues.Policy and services need to consider the couple relationship - together or apart - as well as the parent-child relationship.It also needs to address fathers as well as mothers.Policy makers and commissioners should consider support for both the couple and the parenting relationship. Just targeting the parent -child relationship in the context of ongoing parental conflict does not lead to sustained positive outcomes for children.We need more emphasis on teaching children and young people ways of managing conflict to better prepare them for life ahead.Most parents desperately want the best for their kids. We must put families at the heart of how we organise services and give parents the confidence to seek help if they need it...