Teachers who pick texts that appeal to girls, a lack of books in the home and an expectation that they should be playing outside are all turning boys off reading, new research suggests.
Boys' lack of achievement in reading is not down to "biological differences". Instead there are key factors which lead to them lagging behind girls, according to a report by the Boys Reading Commission.
It says girls are more likely to be given books and taken to the library, while society's expectations and peer pressure can put some boys off.
The report also warns that there is a danger that female teachers will unconsciously choose books that are more attractive to girls.
The commission, set up by the all-party parliamentary literacy group, investigated the reasons why boys remain behind girls in reading.
Figures show that at age seven, 7% more girls than boys are reading at the level expected of the age group, the report says.
By age 11, this gap has widened to 8% and by GCSE level it has increased even further, with 14% more girls than boys achieving at least a C in their English exam.
At the same time, a study by the National Literacy Trust (NLT) for the commission has found that boys are much less likely to enjoying reading than girls.
The report concludes that there are three factors which are associated with boys' under-performance.
It says that the gender gap begins in the home before children start school, with some evidence suggesting that parents encourage girls to read more.
The report cites the NLT's survey which shows that 79.7% of boys are likely to be given books as presents, compared with 85.3% of girls.
It also adds children who see their parents with a book are more likely to want to read themselves.
There is some evidence, the report says, that boys who see their fathers reading, read more than those who do not.
Three-quarters (76%) of schools say that their male pupils do not do as well in reading as female students, according to the NLT's research for the report, with four-fifths (82%) saying they had put measures in place to help boost boys' reading skills.
The report says that reading for pleasure needs to be a key part of teaching and learning in schools, with teachers using books that engage all pupils.
"There is a specific danger that a predominantly female workforce will unconsciously privilege texts that are more attractive to girls," the commission's report says.
Finally, it says that boys are less likely to value learning and reading.
Boys questioned for the study talked about wanting to run around and play, saying this is why they generally spend less time than girls with a book.
It suggests that boys are more likely than girls to think that someone who reads is boring and a "geek", with NLT research showing that almost a fifth of boys (18%) saying that reading is more of a girl's activity.
Chair of the commission Gavin Barwell, Conservative MP for Croydon Central, said: "Our report shows that the gender gap is not biological and therefore not inevitable.
"It is complex - there is no silver bullet - but by promoting reading for enjoyment, ensuring teachers are aware of the reading materials that will engage boys, getting our libraries to focus on those who are falling behind, making sure fathers understand their role as reading role models, getting volunteer male reading role models into our classrooms and using the media to change gender perceptions of reading we can close the gap."