Wow, that's really amazing that children can learn to read even when no one reads to them.
I know! I still don't fully understand how he did it! When he was 18-20 months, he kept bringing me these plastic letters and wanted me to say their names. Then it got boring so I started telling him the phonetic names too. Add to it his addition to Leapfrog videos and at 2 years 4 months I realized he was phonetically reading words I wrote down for him. A week later he decided goofing around with phonetics is too slow and now he just looks at the words and either reads them clearly or mumbles it as close as he can get it. His biggest problem is speech delay. It's hard to read out lout when you can't talk much! lol He is much more sure of his sounds and the whole speech when he's reading.