This video discusses the idea that religious people are happier.
- any sources that support or contradict the claims?
- any scientific papers that address the issue?
It depends on where you look. And exactly as people have said, what defines happiness.
According to some studies, religious people tend to be happier.
But then you look at overall country happiness, and very secular, irreligious nations like the Scandinavian nations are rated as the happiest.
I think it is safe to say that religiousness may not be the main factor in determining happiness, rather other factors, and the correlation is incidental. People searching for a specific correlation and causation will find what they are looking for. In general, a cum hoc ergo propter hoc fallacy at work in both cases.
For instance, in the religious community, there is a ready made support structure in place for religious people.
This may be a bigger contributor to happiness than religion or no-religion.
Yes, according to this study and this book (see chapter 16), religiosity correlates with happiness, though it may be religious attendance and not religious belief that really matters (Chida et al. 2009).
There are many factors that correlate with happiness, and there are effective methods to become happier - religious or not. For more info, and a ton of references, read How to Be Happy (free online).
To add to Larian LaQuella’s answer, this recent study¹ investigated the impact of the a country’s religiosity on the psychological benefits of being religious. In brief, they used data gathered from an online-dating site and investigated the correlations between social self-esteem or psychological adjustment on the one hand and religiosity on the other hand in some European countries. They mainly found positive correlations but these in turn were correlated with the religiosity of the respective country, with the correlations being very low or non-existant, e.g., in Sweden. They conclude:
Another study² reports that it failed to replicate this effect:
Unfortunately I do not have access to this paper to provide further details.
¹ Gebauer et al., Psychological Science 23.2 (2012): 158–160.
There are a number of studies and peer-reviewed books (e.g. Norris and Inglehart, Sacred and Secular: Religion and Politics Worldwide; Stolt et al, Economic Inequality, Relative Power, and Religiosity) which identify a link between religiosity and material insecurity. If you live in a place where with harsher poverty, or which is more economically unequal, then religiosity tends to be higher.
There are some notable exceptions, such as China and Vietnam, which have harsh poverty but low religiosity. This can be explained by the government effectively suppressing religion.
It explains what we see Scandinavia: there is no need for religiosity since those societies are fairly equal. It also explains the United States, which is one of the most economically unequal developed countries in the world. In fact, it's even true of individual states in the US: states with higher economic inequality tend to be more religious, and states with lower economic inequality tend to be less so.
So it seems like a plausible theory that if things are bad, religion helps you cope with it. Opiate of the masses, indeed.