Children (and most people) are afraid of things that they cannot understand or control, and strange or new situations or objects. They can be fearful of many things, because so much of the world is new to them. Fears may also be learned. Sometimes they come from a direct experience with something that hurt, eg. being bitten by a dog.A fear can also be taught by parents, brothers and sisters, playmates, teachers, etc. For example, if the parent always gets afraid when she sees a spider or goes in a lift, the child is likely to be afraid of these things. Fears can also be caused by seeing or hearing about a danger, eg. on TV. Fear of being left alone at night or of the dark is still common among preschool children. Children also have vivid imaginations, and some of the things that they imagine they also believe are real, eg. monsters (especially children under three, who don't yet really know what is real and what is not real).
Young children need to be reassured if something is not real, but it may take them some time to really 
believe there is nothing to be afraid of. It is important that you don't act as if you believe the fears are real. There can be a fine line between pretending to look for monsters yourself, and showing your child that there are no monsters. Children of school age may be worried about burglars, afraid of having no friends, afraid of bullies, anxious about school work, or starting a new school or starting high school.Older children often worry that their parents may separate, especially if they see this happening to friends' families, or if there are a lot of family arguments. Many children worry that a parent may die. Anxiety is infectious and can pass easily from one person to another. Worries and fears can pass easily from parent to child, and from child to parent.
In some ways, this passing of anxieties from parent to child can be helpful to keep the child safe, eg. the child learns that it is not safe to go on the road because you show that this is something dangerous. However, if you are too worried about too many things, the children are likely to be more anxious.
