Argoskin et al., (2014) found a positive correlation between self-esteem and grey matter.
People with low self-esteem tend to have reduced amounts of grey matter in the hippocampus (emotion and control of stress). Therefore their might be a biological element to conformity as people with low self-esteem tend to be more conforming.
An association between damage in the prefrontal cortex and faulty moral reasoning.
Anderson et al., (1999) found two individuals who had suffered brain damage to the prefrontal cortex as babies were unable to understand the difference between right and wrong behaviour and showed personality traits similar to psychopaths.
Authoritarian personality
More likely to obey those in authority and discriminate against those that they saw as inferior