If you type in stress related illnesses in chickens, or some variation of this into Google scholar you'll get quite a lot of studies. Not only can stress switch off a hens egg laying it also makes the susceptible to other diseases that a 'happy' chicken would quickly overcome; just like humans.Dear friends, quick question; do stressed chickens stop laying? It would make sense that they do. I have had one egg from my new girls, the day after we brought them home, then nothing. I am assuming it's just due to stress (and possibly Faverolles aren't the most prolific of layers?), rather than any reproductive issues? Apart from a little cramped, they seem to be doing ok and have settled their differences within the group.
A real problem is the types of things that cause stress and if you read enough about it you may have a different view of much of the advice and keeping condition promoted on the various chicken forums.