There is research evidence that internals are less obedient.
Holland (1967):
He repeated Milgram’s initial study and measured whether participants were internals or externals.
He found that 37% of internals did not continue to the highest shock level, therefore showing some resistance to social pressure.
Only 23% of externals did not continue to the highest shock level.
This suggests that the internals showed greater resistance to authority and therefore to social pressure.
These findings increase the validity of locus of control as an explanation for resistance to social influence.
Furthermore, this idea is backed up by Oliner and Oliner (1998).