Darren Sherkat (Southern Illinois University), has analysed data from the General Social Survey, which is a regular US survey on a wide variety of topics - including (in some years) a test of verbal skills.
The effect is pretty big - belief that the Bible is the word of God has a negative effect on verbal skills similar to the positive effect of being university educated. The effect of simply being a member of a fundamentalist group was smaller - about half as big - but still significant.
So why should fundamentalism be linked to problems with language? One answer is simply that people who have poor verbal skills are attracted to religious fundamentalists - perhaps because it provides a peer group of similarly impaired individuals.
In fact individuals who join sectarian groups as adults do have language problems, but they're not as bad as lifelong members. On the other hand, people who were born into fundamentalism but left as adults are normal.
An alternative explanation is that fundamentalist groups are insular, and discourage the wider social interactions and learning that might help develop social skills. This might explain why non-fundamentalists improve much more on verbal skills as they get older.
Perhaps the verbal skills help explain why fundamentalists earn less.
Here's some more interesting titbits from the analysis - the other factors associated with poor verbal skills in the good old US of A:
- Being younger
- Being male
- Being non-white,
- Being an immigrant
- Being poor
- Not having a university degree
- Being married at any time (although getting a divorce helps repair the damage)
- Having children
- Living in the countryside
- Living in the South.
And what about people with no religious affiliation? Well the good news is that, independent of age, gender, race, education, income, marital status, number of children, and location, they have better verbal skills than people who are members of religious groups!
Sherkat, D. (2010). Religion and verbal ability. Social Science Research, 39 (1), 2-13 DOI: 10.1016/j.ssresearch.2009.05.007
This article by Tom Rees was first published on Epiphenom. It is licensed under Creative Commons.