which is why I used the term non religionist. Don't understand why you think that studies which show people judge non religionist as less likely to be moral, and that people who affirm are less likely to be truthful isn't an argument to move to a general non specific affirmation.
No - from what I read in the article the study focussed entirely on belief in god, not on religiosity.
I'm also rather sceptical of the study as the wording of the question seems rather biased - if the article is correct the terms used were ' a believer in God' and a 'non believer'.
These aren't really neutral and equivalent - surely better to talk about someone who 'believes in God' compared to someone who 'does not believe in God'.
The exact wording in surveys of this type can completely change the fundings, so need to be chosen very carefully.
Unfortunately there isn't a link to the actual published research study so it is rather difficult to judge its quality.
However I remain unconvinced it is relevant as making the following statement:
"I do solemnly, sincerely and truly declare and affirm that the evidence I shall give shall be the truth the whole truth and nothing but the truth."
tells us nothing about the person's belief in god nor their religiosity - I suspect that there are many believers and religious people who chose to affirm rather than give a religious oath, as they will feel that a court of law is a secular rather than a religious institution.