I don't know who to ask for help for what threatens to split up our family. My son's five-year-old son has been behaving in a sexual way towards my daughter's three-and-a-half-year-old son. About two months ago they came to my house and the two boys went into my spare room (the children's room when they stay), so we assumed it was to play. The three-and-a-half-year-old later told his mother that his cousin had made him strip, and had touched his penis and asked him to lie on the bed. His mother was naturally very upset.

My daughter, however, was reluctant to say anything. So I rang my daughter-in-law because I felt that this was not appropriate behaviour for a five-year-old. Also, I was worried that he was being molested, and that this was how he had learnt to behave in such a way. She spoke to my grandson, but he refused to talk about it - he is not very communicative.

We assumed that having been told off he would not do it again, but last Saturday the same thing occurred. My daughter later found that the five-year-old had ripped the clothes off one of her son's toys, and we are very concerned that every time the two families visit we will not be able to leave the boys alone together. I am worried that if it happens again it may cause a rift.

I can completely understand why you would be perturbed by your grandson's behaviour because it steps outside the boundaries we place around the “innocence” of childhood. What concerns me, however, is the automatic condemnation of this behaviour as abhorrent (and that your little grandson gets told off) and the presumption that it could represent something deviant or even worse. With all the adults “freaking out” I am sure that the little boy in question must be completely confused. Anne, I do not wish to belittle your concern but I do want to make a plea for the adults involved here to behave like adults and be calm, rational and understanding in the face of something that is usually not abnormal.

Before I get to the nitty-gritty of your query I just want us to think about why these incidents have engendered such potentially family-dividing panic. Is it because we are awash with stories of child predators so we all assume any sexualised behaviour by our children must mean they have been abused? Or is it because we live in an age where parenting is so fuelled by anxiety that any behaviour that seems out of the ordinary is immediately labelled as deviant? I've said it before and I'll keep on saying it - why are we so ready to presume pathology in children?

I hope, Anne, you can “decatastrophise” this issue enough within your family in order for a sensible discussion to ensue. To begin with, therefore, let's consider what is “normal” gender/sexual behaviour in children. The first and most fundamental point here is that children perceive sex, sexuality and sexual feelings differently to adults. This is a vitally important point and one I feel strongly about after many years in child protection services during which paedophiles have tried to argue that a child “wanted” the sex between them - they absolutely did not. Children do not understand, perceive or desire sex in the way that we do as adults even though they can and do have what appear to be sexual responses and may show sexual experimentation through play.

Sexual development and sexual play are natural and healthy processes in children, with even babies touching and rubbing their own genitals, and baby boys having erections. Development continues, with five to seven- year-old children becoming interested in body parts and functions and some exploratory sexual play beginning. From around eight years onwards children will start to link such behaviours with concepts of love and affection and questions come thick and fast. With the onset of puberty the focus is on relationships and sexual feelings become stronger and more akin to those of adults.

I suspect that there is nothing sinister behind your grandson's behaviour. He is at an age when he is clear about gender differences and fixated with his genitals. This is normal and he needs to be enabled to feel comfortable about it - not guilty or ashamed. What he did was exploratory play with his trusted cousin (who at 3 isn't quite as clear about such issues) and he needs to be helped to understand that while he is not bad or naughty, he must know that genitals are private and his play is not appropriate. Some calm and non-intrusive supervision might help to gently steer him away from this particular game in time.

What he has done is no more wrong than the “doctors and nurses”/“mummy and daddy” play that many children engage in and which can include incidents of “I'll show you mine if you show me yours”. However, the more he is made to feel naughty, the more he will behave like this in increasingly furtive ways. See this as an opportunity for him to be helped to understand his body. There are many wonderful books that help children and parents to find a common language for these important conversations (I love The Body Book by Claire Rayner).

In general there is no need to be worried about sex play between children who are roughly the same age and size. Alarm bells should ring if they are doing things that children of that age just do not know about or are overtly sexual, if they have a preoccupation with sexual interactions, or if they are are hostile, aggressive or hurtful to themselves or others. Your grandson, Anne, is merely showing curiosity with his play (and this includes ripping the clothes off the doll to look at its body) and this needs to be understood from his perspective and handled sensitively. For him to be made ashamed is the first step towards causing him some bigger problems with sex and sexuality in later life.

Finally, it is important to think about your younger grandson and my advice would be to manage his experience in exactly the same way - calmly and without the sort of panic that might make him feel guilty and anxious. He also can be helped to understand that genitals are private and that if he doesn't want to play a game, that is fine and he should say so. Most fundamentally, it is important to preserve a positive, relaxed and trusting relationship between these two boys who are clearly happy being friends.

If you have a family or psychological problem, e-mail Tanya at drtanyabyron@thetimes.co.uk

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