People raised in a country were the government spies on its citizens, encourages selling people out, and kidnaps dissenters are more likely to lie for personal gain.
Interesting assertion. How about some evidence to support it? Obscuring disagreement with the government to avoid punishment is different from cheating for gain.
My guess is this is more an effect caused by Stasi, and not the communism/capitalism divide.
As far as I know, every communist country had oppressive secret police that engaged in many forms of repression. It is a practical necessity of the system. Not so capitalism, so if you want to attribute the cheating to the Stasi and repression it is related to the communist / capitalist divide.