Copy (without formatting) from this blog post: https://www.atheismuk.com/bsas-growth-non-religious
Headlines of the British Social Attitudes Survey (BSAS) for 2016 were released this week showing the growth of non-religious. (1) The media has covered them widely. Those responding ‘no-religion’ to the question on religious affiliation were 52.8% of the interviewees (weighting corrected). This is the highest figure reported by the BSAS since it started in 1983. The Scottish Social Attitudes Survey shows an even higher figure of 58% non-religious. (2)
Growth of 'no religion' is driven by generational differences
The BSAS has 34 years of survey data. So I've made projections of where the current trends will take us if they continue. This suggests that in the next 10 years or so those who identify as ‘Christian’ will be at the same level as ‘no religion’ was 45 years ago. Importantly, generational differences drive the slow trajectory of growth and decline in the BSAS data. Older generations are typically more religious than younger ones. As older generations die they are replaced by the increasingly irreligious younger generations. (3) This trend has produced a slow shift within the population.
Immigration bolsters Christian figures
Immigration affects the Non-Christian religious and Christian figures. The Non-Christian category has grown because of the arrival of people who are more likely to be religious than is typical for the UK population, along with higher birth rates in those communities. There has also been an influx of Catholics and Pentecostals that has slowed the decline of the Christian category.
Proportion of atheists in the 'non-religious' category
The proportion of atheists in the ‘no religion’ category is not easy to determine. So I’ve added a red dotted line at half the no-religion trend line to indicate the likely atheist population. This suggests that in the next 20-25 years atheists will be a larger proportion of the population than Christians in the UK.
However the assumption that half of the ‘no religious’ are atheists is questionable because many surveys do not ask about belief. So the respondents are as likely to be expressing their identity as their beliefs. It’s better to think of it as between 40% and 60%.
The lower 40% 'no religion' figure is attributable to Linda Woodhead’s research published last year which identified 41% of no religionists as ‘convinced atheists’. (4) Using the ‘Convinced atheists’ category is effectively a measure of those who self-identify as atheists. Many people who are effectively atheist or agnostics do not identify as atheist because of the values they perceive to be associated with it. So the 40% figure is probably an underestimation.
The 60% 'no religion' figure comes from Sarah Wilkins-Laflamme’s research which showed 62 per cent atheist, 26 per cent agnostic and 12 per cent unchurched believers in God from BSAS data. (5) This gives much higher figures than most other assessments so I’ve adopted the 60% value as the upper limit.
Longitudinal surveys strongly indicate non-religious trends
The exactness of the numbers in surveys like this is contestable because survey design can have a significant effect on the survey’s results. However, the trends in consistently undertaken longitudinal studies such as the BSAS do give a strong indication of change over time.
3) Crockett, A. and Voas, D., Generations of decline: religious change in 20th-century Britain. Journal for the Scientific Study of Religion. 45 4 (2006): http://dx.doi.org/10.1111/j.1468-5906.2006.00328.x
4) Woodhead, Linda., The rise of ‘no religion’ in Britain: The emergence of a new cultural majority. Journal of the British Academy. 4 (2016): https://www.britac.ac.uk/sites/default/files/11%20Woodhead%201825.pdf
5) Wilkins-Laflamme, Sarah., The remaining core: a fresh look at religiosity trends in Great Britain. The British Journal of Sociology. 67 4 (2016): http://dx.doi.org/10.1111/1468-4446.12205