4. HORMONES AND BEHAVIOR
237
that androgens and estrogens acting during the larval, embryonic, and
fetal periods are influential in the patterning of the behavior displayed
during adulthood.
These many actions of the same hormones are consistent with the
importance that has been attached to the character of the tissues on
which the hormones act. The information we have brought together reinforces the conclusions expressed by Florkin (418a) at the end of his
chapter on the evolution of biochemical constituents, by Medawar
(419) in his consideration of the evolution of viviparity, and by Beach
(420) in his discussion of the evolution of the relationship between the
gonadal and pituitary hormones and courtship and mating behavior in
male animals. The substance of these conclusions was formulated by
Florkin when he was writing about endocrine relationships to organ
functioning: "L'evolution a souvent utilise pour une nouvelle fonction
une substance dejä existante en suscitant Tapparition d'un nouveau
Systeme biochimique recepteur de son action" (418a).
Beyond this generalization are several points which broaden the
picture that has been created. We find for example, particularly in
mammals but to some extent in birds (7, 421-423),
an "intrusion" of
psychologic influences, with the result that an investigator cannot always
be sure where hormonal influences leave off and psychologic influences
begin (7, 53). Such a development may well account for the difficulties
in ascertaining the role of hormones in the induction of parental behavior
(pages 218, 228-230). Something like this may contribute to the difficulty in arriving at an understanding of the relationship between the
gonadal hormones and erotic behavior in man. It is very clear that in
female primates an expanded period of receptivity has developed, first
from the time of ovulation into the follicular phase and then into the
luteal phase (9, 424). Beach (317, 420, e.g.) has discussed the problem
in several places, stating that "evolutionary changes in the direction of
increasing corticalization of sexual functions seem to be associated with
increasing complexity and modifiability of the individual's sexual patterns, and also with a decreasing reliance upon gonadal hormones for
sexual activation and performance."
The problem is presented by Bleuler and Stoll (3) in the discussion
of the psychologic manifestations of hyper- and hypoactivity of the
adrenal cortex in man. In writing about the highly variable and unpredictable emotional symptoms of patients with Cushing's syndrome and
of patients treated with cortisone or ACTH they state: "We are not
dealing simply with an expression of an endocrine stimulus or psychic
function, but with highly personal reactions to this stimulus. These reactions depend not on the endocrine stimulus alone, but also on many
237
that androgens and estrogens acting during the larval, embryonic, and
fetal periods are influential in the patterning of the behavior displayed
during adulthood.
These many actions of the same hormones are consistent with the
importance that has been attached to the character of the tissues on
which the hormones act. The information we have brought together reinforces the conclusions expressed by Florkin (418a) at the end of his
chapter on the evolution of biochemical constituents, by Medawar
(419) in his consideration of the evolution of viviparity, and by Beach
(420) in his discussion of the evolution of the relationship between the
gonadal and pituitary hormones and courtship and mating behavior in
male animals. The substance of these conclusions was formulated by
Florkin when he was writing about endocrine relationships to organ
functioning: "L'evolution a souvent utilise pour une nouvelle fonction
une substance dejä existante en suscitant Tapparition d'un nouveau
Systeme biochimique recepteur de son action" (418a).
Beyond this generalization are several points which broaden the
picture that has been created. We find for example, particularly in
mammals but to some extent in birds (7, 421-423),
an "intrusion" of
psychologic influences, with the result that an investigator cannot always
be sure where hormonal influences leave off and psychologic influences
begin (7, 53). Such a development may well account for the difficulties
in ascertaining the role of hormones in the induction of parental behavior
(pages 218, 228-230). Something like this may contribute to the difficulty in arriving at an understanding of the relationship between the
gonadal hormones and erotic behavior in man. It is very clear that in
female primates an expanded period of receptivity has developed, first
from the time of ovulation into the follicular phase and then into the
luteal phase (9, 424). Beach (317, 420, e.g.) has discussed the problem
in several places, stating that "evolutionary changes in the direction of
increasing corticalization of sexual functions seem to be associated with
increasing complexity and modifiability of the individual's sexual patterns, and also with a decreasing reliance upon gonadal hormones for
sexual activation and performance."
The problem is presented by Bleuler and Stoll (3) in the discussion
of the psychologic manifestations of hyper- and hypoactivity of the
adrenal cortex in man. In writing about the highly variable and unpredictable emotional symptoms of patients with Cushing's syndrome and
of patients treated with cortisone or ACTH they state: "We are not
dealing simply with an expression of an endocrine stimulus or psychic
function, but with highly personal reactions to this stimulus. These reactions depend not on the endocrine stimulus alone, but also on many