The compulsive symptoms of a child with an ordering obsession can include the excessive need to line up, sort, count, hoard, or create symmetry with any number of different objects in the home or at school. From the bottles of soda in your refrigerator to the books and pencils on his desk or the pillows on the living room sofa, your child's need to put things in order or make things symmetrical can apply to virtually anything, anywhere.

Not All Ordering Is OCD

Some ordering behavior is perfectly normal behavior; it may even be a cause for pride for a parent who maintains strict standards of perfectionism in her home. Consider Johnny, who has to line up his pencils in a prearranged order, always largest to smallest, before starting his homework. If Johnny tries to begin an assignment without ordering his pens and pencils in this manner, he becomes anxious and unable to do his work. Johnny has the same “rule” for the books on his shelves. One book can't be taller than another as they move down in size from right to left. This ordering is necessary before Johnny can feel at peace in his own room.

Johnny's ordering behaviors, although they could reflect the lower end of the spectrum of severity of OCD symptoms, should not be a cause of concern for his parents unless they impact negatively on his ability to function.

Order, Numbers, and Symmetry

A common issue for the child with OCD who has an ordering compulsion is a strong preference for even rather than odd numbers (or vice versa). Picture Irene, age seven, whose compulsion for symmetry is triggered when she comes upon an odd number of ceramic dogs arranged asymmetrically on her grandmother's coffee table, three figures instead of two or four, arranged randomly. In math class, Irene faces another ordering-related dilemma when she's called on to come up to the blackboard to write out an answer to the equation (2 × 4)3 and the presence of a three on the board makes her unable to leave her seat.

Confronted with either of these triggers, Irene experiences an intense spike in her anxiety level. At her grandmother's house, she feels compelled to remove the “extra” dog on grandma's coffee table. At school, Irene wants to change the number three following the equation on the blackboard to an even number. If she's not permitted to do either of these things, Irene's anxiety grows even more intense.

But even if Irene can make these changes, her relief is likely to be short-lived. That's because the cause of her anxiety goes well beyond a simple math problem or the arrangement of ceramic figures on Grandma's table. Those are her triggers. The underlying problem is anxiety that manifests in the symptoms of OCD.

And the behavior is identical for someone with the opposite, odd-numbered manifestation of this same compulsion for order. Sixteen-year-old Harriet can only deal with odd numbers in her immediate world. She had nine different alarm clocks in her bedroom, each set fifteen minutes apart in the two hours before she had to leave for school. Everything must be divisible by three or she becomes uncomfortable. Three pencils, three of each color of clothing in her drawers, and so on.