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WILLIAM C. YOUNG
confinement. Whatever the species, environmental control at the time
of the observation or test must be rigid. Uncomfortably high or low
temperatures and unusual sounds should be avoided. Animals should
be accustomed to being handled and they should be cage adapted, that
is placed in the cage, enclosure, or apparatus where the test is to be
given a few minutes before it begins. In mating tests this is more
important for the male than for the female, and investigators have long
been aware that the female should be brought to the cage of the male
(76, 77). The recency of sexual activity is important, particularly when
males are being used. A number of the newer articles in which the
relationships between the sexual act and subsequent behavior is described are cited by Young (9). The phase of the cycle in females should
be known, not only because of the direct relationship of the phase to
sexual behavior, but also because the females of some species display
aggressive behavior during the diestrum and are cyclic in this respect
(78-80).
The behavioral literature of the last decade is replete with reports
of what are often lumped together as experiential factors and their
influence on behavior. Included are various types of sensory deprivation,
social isolation during infancy, maintenance in enriched and restricted
environments, immobilization, crowding, exposure to noxious stimuli such
as electric shock, high and low temperatures, noise, and handling or
gentling. Selected fishes, birds, and mammals, including monkeys and
chimpanzees, have been used. Much of the literature is cited by Denenberg (81), and other articles have appeared more recently (75, 82-90).
Many of the results are equivocal if not contradictory; nevertheless, the
evidence is impressive that in birds and mammals life experiences, and
particularly those during infancy and the juvenile period, do much to
shape the character of behavior displayed later. The point is especially
important for the investigator as he selects animals for studies of the
relationships between the hormones such as those from the thyroid,
adrenal cortex, and gonads, the secretion of which is regulated by
hypothalamic-hypophyseal activity.
In the development of methods for studying the relationships between
the hormones and behavior, the investigator must be on guard, again
against factors many of which are less important for the student of other
responses to hormonal action. Much of the behavior influenced by hormones is complex, much is displayed in a rapid succession of movements,
much cannot be observed and recorded except by watching the animals,
and within a species much is extremely variable from individual to individual. Under such circumstances, the matter of observer reliability is
important and is a point over which scrupulous watch should be kept.
WILLIAM C. YOUNG
confinement. Whatever the species, environmental control at the time
of the observation or test must be rigid. Uncomfortably high or low
temperatures and unusual sounds should be avoided. Animals should
be accustomed to being handled and they should be cage adapted, that
is placed in the cage, enclosure, or apparatus where the test is to be
given a few minutes before it begins. In mating tests this is more
important for the male than for the female, and investigators have long
been aware that the female should be brought to the cage of the male
(76, 77). The recency of sexual activity is important, particularly when
males are being used. A number of the newer articles in which the
relationships between the sexual act and subsequent behavior is described are cited by Young (9). The phase of the cycle in females should
be known, not only because of the direct relationship of the phase to
sexual behavior, but also because the females of some species display
aggressive behavior during the diestrum and are cyclic in this respect
(78-80).
The behavioral literature of the last decade is replete with reports
of what are often lumped together as experiential factors and their
influence on behavior. Included are various types of sensory deprivation,
social isolation during infancy, maintenance in enriched and restricted
environments, immobilization, crowding, exposure to noxious stimuli such
as electric shock, high and low temperatures, noise, and handling or
gentling. Selected fishes, birds, and mammals, including monkeys and
chimpanzees, have been used. Much of the literature is cited by Denenberg (81), and other articles have appeared more recently (75, 82-90).
Many of the results are equivocal if not contradictory; nevertheless, the
evidence is impressive that in birds and mammals life experiences, and
particularly those during infancy and the juvenile period, do much to
shape the character of behavior displayed later. The point is especially
important for the investigator as he selects animals for studies of the
relationships between the hormones such as those from the thyroid,
adrenal cortex, and gonads, the secretion of which is regulated by
hypothalamic-hypophyseal activity.
In the development of methods for studying the relationships between
the hormones and behavior, the investigator must be on guard, again
against factors many of which are less important for the student of other
responses to hormonal action. Much of the behavior influenced by hormones is complex, much is displayed in a rapid succession of movements,
much cannot be observed and recorded except by watching the animals,
and within a species much is extremely variable from individual to individual. Under such circumstances, the matter of observer reliability is
important and is a point over which scrupulous watch should be kept.