Think back to your own childhood. Did you have a security blanket? Do you remember why it was so important, or how it made you feel?

    In the simplest terms, a security blanket is any toy or object that a child clings to for comfort or reassurance. The most common are the blankets children carry with them seemingly everywhere, but stuffed animals and sometimes dolls or toy cars are also prized. Children often refuse to be separated from the objects, and indeed removing the security blanket or object from their grasp provokes severe emotional outbursts.

Psychologists believe the security blankets - also referred to as transitional objects - occupy a supporting role at a critical time in a child's emotional development. Transitional objects were first theorized by British psychoanalyst Donald Winicott, who identified their role in helping children move towards independence. In early development, Winicott reasoned, children see themselves and their mother as a whole unit, with the mother fulfilling the desires the child expresses. This creates a misperception, called subjective omnipotence, in which the child believes his wish created the object desired.

As a child's growth continues, usually at around eight or nine months, it begins to realize the separation between itself and the desired objects. This feeds an awareness that the mother is different and apart from the child, and the child often looks for something to fill the void perceived as left in the wake of the separation.

The transitional object is usually something dependably available, to which the child feels a certain loyalty and responsibility. Because blankets, dolls, stuffed animals and toys are often presented to children as gifts, they feel a bond with the particular object. The object represents, by way of stability and loyalty to the child, the aspects of mothering the child craves. In fact, however, the child is focusing independence through the object, providing itself with the emotional reassurance necessary to make the jump to the limited independence of childhood.

Transitional objects are commonly needed at times when the mother would most commonly be found or when reassurance is most desired. At bedtime, encountering new settings such as school or day care, and when meeting new people are all events in which the transitional object becomes most prized for its ability to reflect motherly protection. For this reason, security blankets normally occupy the point in childhood in which mothers "vanish" for increasingly long periods of time: mothers return to work, begin taking the child to preschool or babysitters, or allow themselves time of their own.

The Psychology Department of the University of Wisconsin-Milwaukee has also done extensive research on the subject, and many of their results echo Winicott's theories and expand them even further. Led by Professor Richard H. Passman, the department's results suggest that security blankets actually help children adapt to new situations and react more positively to challenges. By way of evidence, a 1997 study by the American Psychological Association revealed that children who brought along security blankets to medical visits fared as well when their mothers were not present as when the mothers were available.

And security blankets are more common than most people realize, though not for the reasons that have traditionally been believed. A common misconception exists that children create or designate security blankets to compensate for a lack of affection or nurturing by the mother. In fact, the opposite is true. As parents care for their children, when inevitably the time for separation comes, the child is quick to try and compensate not for the lack of affection but rather to continue it. Children deprived of emotion, studies show, sadly learned to "do without" and did not try to compensate with other objects of affection and security.

A recent poll showed that as many as 60% of children in the United States have some form of security object. While blankets and stuffed animals are the most common, some children even adopt ordinary household objects, melodies, and even simple everyday words. Experts caution parents to allow their children to let any security blanket phase run its course. They advise parents to warn babysitters and teachers to let the security blanket be, and to grant the child full access and contact whenever possible.

Finally, the security blanket occupies a unique and charming place in American pop culture. Cartoonist Charles Schultz in the comic strip Peanuts first popularized the idea of the literal "security blanket", when he characterized strip regular Linus Van Pelt as inseparable from his beloved blue blanket. More recently, the nickname "wubby" has grown in popularity for any security object, inspired by the 1983 film comedy Mr. Mom. Much of the film's story revolves around a young boy's efforts to part with his beloved - if tattered - throw blanket.