My team chose snowflakes. We had each person in the "audience" (our class) create a paper snowflake to demonstrate that, just like every snowflake is different, every person who stutters in different. The way the stutters appear (blocks, part word reps, whole word reps, etc) are different, sometimes secondary behaviors are exhibited, the onset can vary, some people stutter more when they read, some stutter less when they read, etc.
In the demands-capacity theory of stuttering, it is believed that a child can be predisposed to stuttering by having the right precipitating factors (gender, age, familial link, etc). Just like a snowflake is predisposed to becoming a snowflake by being a water droplet in the atmosphere. In the demands-capacity theory, a child who stutters (CWS) exhibits dysfluencies when the demand on his/her speech outweighs his/her capacity. For instance, a child who is quite young (age 2-3) who is learning language at a rapid pace and can think faster than he/she can talk may begin to show dysfluencies when his/her demand for language is greater than his/her capacity of motor planning. The atmosphere must be at the right temperature to make a snowflake, which shows that the environment played a role, but did not cause the snowflake. Parents DO NOT cause stuttering. It's simply environmental factors (both internally within the child and externally when natural language learning is occurring) coupled with predisposition.
Some children may stop stuttering for a while and then begin again. Typically when they begin again, it is more severe and will require speech therapy. These kids would be more like sleet (when the snowflake melted and then re-froze).
Some children continue to stutter. The theory that we chose to explain those who perpetuate their stutters is called the multifactorial theory. The multifactorial theory suggests that heredity, brain development, personality, learned behavior, and environmental factors all converge to cause and perpetuate stuttering. The elements of temperament and environmental influences fit well with ideas of how stuttering is maintained once it begins. Many times parents report that children who persist in stuttering are often sensitive. A child who is sensitive about his/her pattern of speech being dysfluent may tense up creating more dysfluencies and more stress about the dysfluencies and then it "snowballs". The environment can also play a role. If the child is in an environment where speech is used at a slower rate or there isn't quite as much demand on his/her speech then he/she may be able to relax enough to allow his/her brain to recognize the speech pattern and speak at a more fluent rate. If the environment is a more stressful situation where people are finishing your sentences or you have a large audience or you are being timed (speech), then you may feel more stress and more stutters will come out. Now, if that type of environment perpetuates itself and the child is in that type of environment long term, then his/her stutters may persist.
This comparison and these theories are on the tip of the iceburg (pun intended) when talking about fluency or stuttering. If you have more questions about fluency or stuttering, please feel free to message me or speak with your speech therapist!