The Effects of Hormones on Behavior

The study of hormones and their effects upon individual and group behaviors
is of immense interest to psychologists. Hormones represent the biochemical
control signals for much of animal and human behaviors. Understanding
precisely how hormones affect individuals, both psychologically
and physiologically, could be of great value in comprehending many different
human behaviors, in treating abnormal behaviors, and in helping individuals
to cope psychologically with disease and stress. The hormonal control
of behavior in humans and in many other animal species has been
extensively studied, although much research remains to be performed.
Hormones have been clearly linked to reproductive behavior, sex-specific
behavioral characteristics, territoriality and mating behaviors, physiological
responses to certain external stimuli, and stress.
The pineal gland, located in the posterior cerebrum, releases the hormone
melatonin, which regulates the body’s circadian rhythms and possibly
its sexual cycles as well. Melatonin is normally synthesized and secreted beginning
shortly after dusk throughout the night and ending around dawn. It
thus corresponds with the individual’s normal sleep-wake cycle. Melatonin
may play an important role in humans adapting to shift work. It is promoted
as a nutritional supplement to help people get a good night’s sleep.