It is a widely held belief that caffeine stunts growth, but there are no scientific studies to support this claim. However, caffeine is generally not recommended for children because it can cause many side effects such as upset stomach, jitteriness, nervousness, headaches, difficulty concentrating, insomnia, increased heart rate, increased blood pressure, and dehydration. Because children are smaller than adults, it takes much less caffeine to cause these effects in a child.
I often see children on the line at Starbucks- ordering Decaf drinks and thinking they are safe. All decaffeinated coffee has some caffeine (just less than regular). Starbucks decaf coffee has especially high levels of caffeine. In my opinion, parents should not give their children caffeine.