Originally Posted by TheSquealer

Ironically, this is a common feature of ADD as well. ;)

They can obsess 100% and work long days, completely focused on what they are interested in. That behavior does not necessarily denote intelligence. Should intelligence and that behavior co-exist, that does not necessarily indicate a causal relationship between intelligence and ones ability to focus. Children focus intensely on anything and can play intensely for hours and have much lower IQ's than adults.