The research on dishonesty

This question is in regard to the explanation power of the conducted experiments to prove the self-concept maintenance theory in Mazar et al.’s "The Dishonesty of Honest People?" (Verschuere, et al. 2018).

Am I correct in thinking that the experiments are not controlled enough and their claim that one result might be consistent to their theory does not mean that the motives behind the behaviours observed in the results cannot be due to other forces?

In one experiment where they they claim to test the hypothesis directly that one is aware of it’s dishonest behaviour, but because of the cognitive mechanism one is able to maintain ones self concept is actually full of flaws. E.g. we do not know whether it was controlled for individual differences, since the sample size is small, randomization might still lead to heterogeneity between groups.

References

Verschuere, Meijer, Jim, Hoogesteyn, Orthey, McCarthy, Skowronski, …, Ezgi. (2018). Registered Replication Report on Mazar, Amir, and Ariely (2008). Advances in Methods and Practices in Psychological Science. 1(3), 229—377. https://doi.org/10.1177/2515245918781032