SEROTONIN MAKES THE BRAIN FEEL
BAD.
FOR SOME PEOPLE, THIS
MAKES THEM DEPRESSED.
THEY FEEL BAD ABOUT THEMSELVES.
FOR OTHER PEOPLE,
THEY MAY FEEL ANXIOUS.
THEY FEEL BAD ABOUT
THE WORLD AROUND THEM.
BUT FOR OTHER PEOPLE, SEROTONIN
CAN BE INVOLVED IN HOSTILITY
WHICH, OF COURSE, IS
FEELING BAD ABOUT OTHER PEOPLE.
PROBABLY AS A RESULT OF THAT,
SEROTONIN HAS ALSO BEEN LINKED
TO VIOLENCE.
VIOLENCE, OF COURSE, IS THE
PHYSICAL ACTING OUT OF FEELING
BAD ABOUT OTHER PEOPLE.
IT'S THE EXACT OPPOSITE OF
BEING A SOCIAL INDIVIDUAL.
AND THERE HAVE BEEN QUITE A
FEW EXPERIMENTS SHOWING ALTERED
SEROTONIN LEVELS IN THE
BRAINS OF VIOLENT CRIMINALS,
PEOPLE THAT HAVE BEEN
INCARCERATED 
AND ALSO PEOPLE WHO HAVE
COMMITTED SUICIDE WHICH IS YET
ANOTHER FORM OF VIOLENCE.
IN THAT CASE, AGAINST THE SELF.
SO SEROTONIN HAS BEEN LINKED
TO MANY OF THESE DIFFERENT
BEHAVIORS WHICH ARE
DISTINCT FROM ONE ANOTHER 
AND YET ALL RELATED IN THAT THEY
HAVE TO DO WITH THIS EMOTIONAL
SENSITIVITY, THIS EMOTIONAL
FEELING BAD SORT OF SENSE.
