Members of The Church of Jesus Christ of Latter-day Saints (often called Mormons) usually cross or fold their arms when they pray mainly as a learned habit meant to show reverence and reduce distraction, not because of any formal scriptural command.

Not a scriptural requirement

There is no directive in Latter-day Saint scripture that says people must cross or fold their arms while praying, and people can pray in any posture (kneeling, standing, sitting, etc.). Church publications describe folding arms as part of “formal” or customary prayer, but treat it as a tradition rather than a commandment.

Taught in children’s classes

The gesture is strongly reinforced in Primary, the children’s program of the church, where manuals explicitly teach kids to “fold [their] arms, close [their] eyes, and bow [their] heads” to get ready to pray. Teachers also encourage arm-folding because it keeps children’s hands still so they are less likely to fidget or bother others during prayers.

Habit that continues into adulthood

Because nearly all LDS children are taught this posture from a young age, many continue doing it automatically as adults whenever they pray in groups. Among Latter-day Saints, this has become a common “default” prayer posture, even though individuals may also clasp their hands or simply rest them at their sides.

Symbolism and cultural roots

Some LDS and Christian writers connect folded or crossed arms with older Christian traditions of crossing the arms over the chest as a sign of humility or contrition before God. Others note that many religions use some kind of standardized hand position in prayer, and in LDS culture, folded arms simply function as the local sign of respect and focus.