Gifted Issues Discussion homepage Forums Identification, Testing & Assessment Will learning to read and write improve IQ scores?

Thank you so much for all the insight. As I posted before, I am going to wait a little while longer and retest - maybe use another method than WPPSI.
My son said (at that time) that there were flashcards with words and pictures in the test - and that he could not read the words and had to ask to see the flash card again - for example a picture of a fish with a word "Lion" written on it - and he was asked to tell the tester if the word and the picture matched (this is what I understood from him). Another tricky question was to identify the odd object in a picture - it had a lot of things in one color and a single object being in another color. He is diagnosed as colorblind for shades of Red and Green, so he really cannot see some of the shades of color and we did not have that diagnosis at testing time.
I am beginning to believe that testing during early childhood can have a wild range of results that reflects a child's mood, knowledge base, abilities and also the child's understanding of what the testing is about (he was told that he was going to a room to play some "puzzles and fun games" by the tester and he was set to have "fun" rather than finish tasks in a timely manner).
The private school we tested for rejected my son based on the IQ test, which is why I had a suspicion that a deviation in number for processing speed could well be an indicator of a LD (in their eyes atleast) and they did not want to do the "hard work" of educating a student who might require special effort.
I am glad that I came out of lurkdom to ask this question. And I am overwhelmed that so many of you took so much time to respond to me. Thank you!