r {554} the head of temperament. Only that to-day, with some
knowledge regarding the internal secretions of the "endocrine glands",
we should be inclined to connect temperament with them, rather than
with blood, bile, etc. Take, for example, the secretion of the adrenal
glands, that we found to be poured out during fear and anger and to
have so much to do with the bodily condition of readiness for violent
action and probably also with the "stirred-up" emotional state. What
is more likely than that individuals differ in the strength of their
adrenal secretion or in the readiness with which the glands are
aroused to pour it out into the circulation? The excitable individual
might be one with over-active adrenals. And in the same way the
strenuous individual might be one with an unusually active thyroid
gland, since there certainly seems to be some connection between this
gland and the tendency to great activity. There are several other
glands that possibly affect behavior in somewhat similar ways, so that
it is not improbable, though still rather hypothetical, that chemical
substances, produced in these glands, and carried by the blood to the
brain and muscles, have much to do with the elusive traits that we
class under temperament and personality.

Once more, consider the instincts in relation to personality.
Undoubtedly these instinctive tendencies differ in strength in
different individuals. One is more gregarious than another, and this
is an important element in his personality. One is more assertive and
masterful than another, one is more "motherly" than another, more
responsive by tender and protective behavior to the presence of
children or others who need help. One is more prone to laugh than
another, and the "sense of humor" is admitted to be an important
element in personality. And so on through the list; so that
personality can be partially analyzed in terms of instinct.

{555}

Has _intelligence_ anything to do with personality? It certainly has,
in many ways. One who is slow in learning adapts himself poorly to
other persons and remains out of touch with his social environment.
"Tact" depends partly on instinctive liking for society, no doubt, but
partly on the ability to perceive what others want, and on the
imagination to put yourself in their place. High principles require
the ability to reason things out and see them in perspective.
Statistical studies of the rulers of Europe, for a period of several