Massey University literacy expert Professor Tom Nicholson said having dads as reading role models was hugely important.
"Boys tend to dislike reading much more than girls and they over-represent in remedial reading classes. So dads reading, to boys especially, is a really important message to get out there to New Zealand fathers," he said.
Fathers' language was often more directive and informative - using shorter sentences but more complex words - than mothers, he said. Having both parents reading to them expanded children's vocabulary and helped them to do better in school.
Auckland father Anthony Keesing said he was the main reader for his son William, aged 2.
"The book is often just a platform. I put him and people he knows into the stories and all that sort of stuff so that he identifies with the story," he said. "Then we use the books for games like 'same as', in which he has to find things that are the same as other things. For example, find another bird, or a fish, or a clown.
"When it comes to this, I am a bit of a true believer. Boys, especially, need dads who engage with their reading. I have met many boys who think reading (and especially writing) is a girl thing, and why wouldn't they? They are read to at home by mostly mothers. Their teachers are mostly women. They can be at secondary school before they get their first male teacher. In my view, boys need to see that reading (and writing) are male things. About fun and imagination, but also about competence, mastery and success."
He said William already had about 200 books, mainly from op shops.
"When I first bought him books, he started out eating them. Then he started ripping them, then he stacked them in towers, and now he looks at books by himself for maybe 20 minutes at a time," Mr Keesing said.
"When he's done with a book, he often gives it a good hurl, which I encourage. Why not? I don't really care what he does with his books as long as he engages with them."