I feel it does more than that too. If there is no technical security measures taken it seems less of an offense to cheat, if you see real effort to stop you it makes it feel more wrong even if you can get around it.
My intuition is the opposite. If someone said "No cheating, on your honor" then I would probably feel much more hesitant to cheat. On the other hand, if I see you're trying to prevent cheating then I feel almost obliged to defeat the measures you thought could contain me.
This only works when no one cheats. When someone cheats easily and gets ahead with no consequence, i doubt "honor" is quite as powerful.