"The issue of divided loyalty is so important and so painful when you're a child. Are you allowed to like the new step-parent? Can you love them? Can you hate them? I really liked my father's second wife. When he left her, I thought I can't do this again. As soon as my first stepfather had a child with my mother, he didn't want to know us. When my second stepfather turned up and gave us this `Now, as your stepfather...' talk, we thought `Oh, f---k off. Who are you?'"
Paul is 11 and understands all about divided loyalties. "This has been my life - coming to my dad's at weekends, being at my mum's all week," he says in Channel 4's new six-part series, Stepkids. "It's always happy and sad. Sometimes you get upset: you don't know if you're coming or going."
The series gives a voice to all those involved in stepfamily life in a way never seen before in British documentaries. The idea sprang from one moment in a Channel 5 documentary, says executive producer Kathy O'Neill, when the reporter asked a group of girls in Wakefield, "If you could have anything you wanted in your house, what would it be?" One girl replied, "A dad".
The children's testimonies, eloquent, raw and powerful, bear witness to increasingly common childhood experiences: the upheavals of parental separation; their sense of loss, jealousy and rejection; the shuttling between homes; the children's incredible capacity to adapt and love or reject and disrupt; the parental competition for their time and affection - "Double presents, double Christmas presents, double Easter eggs!" as one puts it.
Most of their parents, with some exceptions, are trying desperately to balance everyone's needs. Some by superhuman efforts at understanding, some by subsuming their own needs, some by struggling with the logistics involved in getting to the end of the week. The constant readjustment and negotiation is exhausting.
It's a minefield but not an entirely modern one: before the 20th century, stepfamilies formed by remarriage after the death of a parent were commonplace. Nevertheless statistics are rocketing. Meanwhile stepfamilies are struggling with too little support in a society that's yet to wake up to the fact that parental splits and repartnering could be the norm by 2010.
Relationships in stepfamilies can take two to 10 years to stabilise, according to the National Stepfamily Association, and at least 50 per cent of remarriages which form a stepfamily end in divorce.
But they can work. Research shows the key to children's capacity to cope lies in adults' handling of family change and their recognition that children need to talk.
Parental contact is crucial to a child's view of the world. (If in doubt, watch young Thomas's chin in Working It Out, the third in the series, as he looks at the camera and says he doesn't care that his Dad doesn't visit any more.)
It also helps to recognise the explosive potential of a step-parent assuming the role of a parent too soon, by imposing discipline or adopting uninvited over-familiarity. And that disruptive behaviour is common as children act out emotions they can't otherwise express and put adults' staying power to the test.
Jamie, 11, with a head-spinning web of stepfamilial connections, tells the camera: "People should take more time, not just rush in and having a baby." But life, as his mother reminds him, is rarely that straightforward.
`Stepkids' begins on 24 June, at 9.30pm on Channel 4. Jan Parker is co-author of `Raising Happy Children' (Hodder & Stoughton, pounds 9.99).Reuse content