Children worry. Some worry more than others, but the average child has six or seven intense fears, research shows. Some of these fears vary from culture to culture. Patricia Owen, a child psychologist, travelled around the world comparing children's fears. Writing in Psychology Today, she reported that children from US inner cities are most fearful of gangs, guns and drive-by shootings.

Mongolian children are terrified of dinosaurs, since the skeletons of these great beasts can be found in the Gobi desert. Balinese children, who are taught moral lessons with eerie shadow puppets, are frightened of shadows above all things. Laotian children are spooked by ghosts, but having grown up in a Buddhist culture, don't flinch at the sight of a mummy.

Across all cultures, however, there are terrors of war, nuclear weapons and kidnappers, Owen found.

In the West, researchers have found a predictable fright list, which comes up again and again from study to study. Health, school, disasters, personal harm and future events are areas ripe for anxiety. Children's most intense worries concern war, personal harm disasters, school and something bad happening to family. Their most frequent worries are about friends, classmates, school, health and performance.

In other words, possible events over which children have no control are the most horrifying and intense prospects. Children worry much more about these things than they did a generation ago, according to research, and levels of anxiety thought abnormal in the 1950s are normal today.

TV has a lot of answer for. One of my children saw a film in which a comet hits the earth, causing a tidal wave which wreaks global devastation. She worried about this for months, especially at bed-time, and it still tops her fear-list.

I tried to put this fear in perspective and explain that a comet will never hit the earth - at least not in our lifetimes. My child replied that there was a chance it could happen in our lifetimes, because she'd seen a documentary about comets hitting the earth on the National Geographic channel.

This TV channel, which I used to think of as "safe" viewing, has documentaries that tend to be more anxiety provoking than many fictional programmes. Programmes about hurricanes, tornadoes, killer bees, global warming and so on, play to the deep anxiety children have about environmental disaster.

The same children who are freaked at the thought of environmental cataclysms, may find overt fictional horror entertaining: I have a child who finds Buffy the Vampire Slayer amusing and thinks of Godzilla as a huge, cuddly Barney. But then, vampires and giant monsters are not on children's fear-lists because they know that these things aren't real.

And the character of Buffy is fearless and, usually, in control. She is constantly confronting and overcoming threats through bravery and intelligence, which is why, I think, she is so appealing to so many children.

Obviously, you shouldn't let your children watch Buffy - or any TV programme or film - that is going to make your child feel anxious.

A lot of parents wouldn't let children under 12 watch Buffy at all, but the TV news is probably worse. During the Gulf War, for example, lots of Irish children were terrified by images of the bombing of Kuwait. Take it for granted that no matter how much you try to protect your children, they are going to be afraid of certain things.

And as children grow into adolescence, their fears change and may seem to adults to be focused on less significant things, although they are just as significant and intense for the child. Twelve-to-16 year-olds worry a lot about their appearance, "little things" and their performance in school.

What's the difference between "normal" fear and clinical anxiety in a child? When should a parent worry about a child's worries?

Research shows that children with anxiety disorders have the same number of fears as other children, but that these fears have greater intensity and frequency. One study showed that children being treated for anxiety disorders actually had fewer fears than the average child, but felt them more deeply.

Healthy children have the fears, but they can manage them and learn to stop worrying when they want to. It's the feeling of control over fear that makes the difference. Children who develop psychological problems related to anxiety feel anxiety more painfully, more often, and feel they cannot control their feelings of panic and fear.

Telling anxious children that they are silly to worry is not going to help. Because according to the research, anxious children do not overestimate danger.

Rather, they underestimate their ability to cope with the danger.

Step one in helping your children to manage their fears is not to belittle them. Step two is to talk about the fears openly. Honestly discuss the chances of the occurrence actually happening and talk about what the child and family would do if the scary thing were to materialise.

Remember that children don't like to worry their parents, so they may bury their fears and resist talking about them. When they do express their fears, keep your body language calm and accepting. Be relaxed and show that you don't feel threatened or angry.

Suggest that your child visualise holding the fear in their hands, then putting it somewhere safe. Some parents like to teach their children to talk to God or a higher power about their fears.

An old-fashioned approach was to give the child a religious medal as a kind of amulet, but to some parents that smacks of superstition, not to mention Buffy and her vampire-repelling cross.

Remember, it's important that your children knows that the ability to control their fears is within them and doesn't come from somewhere else.

If your child is going through a worry spell, help your child learn to relax, particularly before bed-time when fears tend to blossom.

Meditation is a great skill, especially learned early in life. A warm soak in a bath with a few drops of essential lavender oil is calming. Turn off the TV at least an hour before bed-time, since TV - whatever the content - is stimulating. Instead, play soothing music. Some children like to listen to music in their bedrooms as they fall asleep.

Most of all, don't worry about your child being worried. It's only when children become so anxious that they cannot cope, that you need to seek help.