Well here's some good news for bookish parents - having big home libraries makes your kids smarter, according to new research.
As part of the study, which was recently published in Social Sciences Research, a team from Australian National University and University of Nevada examined data from the Programme for the International Assessment of Adult Competencies (PIAAC), which measures adult literacy, numeracy and information technology competencies. Participants from 31 different societies, were asked how many books they had in their homes when they were 16 years old, not including magazines, newspapers or schoolbooks.
Average home library size varied between countries, with Estonians topping the list at 218 books on average, compared to Aussies at 148. Norwegian home libraries boasted 212 books, followed by 210 in Sweden and 192 in Denmark. Those in Turkey had on average 27 books, while Chilean and Singaporean home libraries held around 52 titles.
The researchers found that growing up with few books in the home was associated with below-average literacy rates, defined as "ability to read effectively to participate in society and achieve personal goals." The magic number seemed to be the presence of about 80 books, which raised literacy levels to the mean. And while levels increased with the number of reported books in the home, the effects flattened out at around 350 (although I'm going to pretend I didn't read that.)
"The total effects of home library size on literacy are large everywhere," the researchers conclude.
Yep - that's science giving you the go ahead to buy the latest Liane Moriarty.
Unsurprisingly, education, occupational status and reading activities at home were all linked to better literacy skills. However, the results also highlighted that participants benefited from being exposed to books as a teen "above and beyond these effects." That's right, they only needed to be surrounded by the books, not dipping into your copy of War and Peace at age seven like Matilda, in order to benefit.
But bigger home libraries weren't just associated with stronger literacy skills - teens exposed to more books also had better numeracy and digital problem-solving/communication skills. "Our results show that adolescent exposure to books is an integral part of social practices that foster long term cognitive competencies spanning literacy, numeracy and ICT skills," the authors note. And one again it was the presence of books, over and above other factors that mattered. "Growing up with home libraries boosts adult skills in these areas beyond the benefits accrued from parental education or own educational or occupational attainment," they add.
What's interesting about the data, however, is that the effect is loglinear. What on earth does this mean in English? Well, according to the authors, it's the "first few books" that make the greatest contribution to the three kinds of cognitive skills measured. For example, when a library grows from 18 books to 63 books, the literacy gain is higher than when a library grows from 350 to 650 books.
"When bookishness becomes an integral part of early socialisation, it later enhances a specific suite of cognitive skills, through fostering the practice of surrounding oneself with books," the researchers conclude.
If that isn't a reason to visit your local bookshop today, then I don't know what is.