My name is Patrick, and I’ll drop a further two cents. My cents are going to run out soon if I’m not very careful.
The whole issue of literacy is an unclear and controversial one, and different people will hand out different figures. (But then again, so are a lot of other things in the 1st century!) Some such as John Dominic Crossan will argue that at the time 95 to 97 percent of the people were ‘illiterate’; the remaining percentage who was literate would have mostly been upper-class. Since Jesus was from a low-class background, He
must have belonged in that majority, they say.
Philo and Josephus do talk about how children are taught Torah by their parents and how to read it (cf.
De Legatione 210;
Against Apion 1.60; 2.176, 178, 204), however, one could not dismiss the possibility that they were painting an idealized picture and might have had in mind upper-class homes who could afford decent education for their children. But then again, the pursuit of education was not the sole domain of the wealthy and the professional: it could very well be that Philo and Josephus do get something right. For the moment I’d recommend the article
Context, Family and Formation by Craig A. Evans in
The Cambridge Companion to Jesus edited by Markus N. A. Bockmuehl (2001) and in
An Outline of the Life and Mission of Jesus, b. Upbringing and Education in
Jesus Remembered by James D. G. Dunn. Maurice Casey in
Jesus of Nazareth: An Independent Historian’s Account of His Life and Teaching (p. 158-159 ff.) meawhile offers a critique of Crossan’s figures.
For the record, learning to read is a separate skill from learning how to write. Children nowadays learn how to read AND write as a set, but in the ancient world, there are people who can read but can’t write, and people who can mimic letters without understanding what they are writing. So even if we grant that Jesus can read (His actuall skill notwithstanding), it’s a different question about whether He can write.