Inhibition is a late development and is largely a result of education.
If the motor impulses remain strong, or become stronger in the presence of development with exercise, while inhibition remains weak, we have a criminal.
Inhibition is the function performed by the highest and last-formed brain-cells.

These brain cells may be undeveloped either from want of exercise, that is, education, or from hereditary weakness, or, having been developed may have undergone degeneration, under the influence of alcohol, or from hereditary or acquired disease.
Motor impulses, as the springs of action, are common to all animals.

In the lower animals inhibition is external, and never internal or subjective.

In man it may be internal or external.
It is internal or subjective in those whose higher brain centres are well developed and normal.

Their auto-inhibition is such that all their motor impulses are controlled and directed in the best interests of society.
It is external only in those whose higher brain centres are either undeveloped or diseased.