Part One / Chapter 1
Animal and Human Behavior
Can we learn much about our own behavior from studying
that of animals? Can the study of a beetle or a rat tell us something about
man's basic drives? Can we solve problems of psychology or sociology by
devoting our attention to the giraffe, dancing fly, and segmented worm?
Human actions – we tell ourselves – are the products
of conscious mental acts and are thus essentially different from those
of animals. It is vaguely humiliating even to consider the idea of comparison.
We human beings are (as far as we can ascertain) the only creatures to
possess an awareness of self, the only creatures endowed with reason. We
can consciously direct our actions with an eye to the future. We have produced
immensely complex codes of religious, moral, and aesthetic behavior. We
have, by using our ability to think, created complex political and economic
organizations which have no comparable counterparts in the animal kingdom.
We have many truly grandiose cultural and technological advances. What
can the lowly worm teach us which might add to our self-knowledge? The
bee, the whale, the lion – these are living creatures like ourselves and
to that extent related to us. But when it comes to assessing ourselves
and to understanding a creature as obviously superior and fundamentally
different as man, surely they can be of little
(original book page 18)
use or, at best, can enable us to draw nothing more than
unimportant and superficial parallels.
On the other hand, the theory of evolution is largely
accepted. Indeed, actually it is no longer a theory and has become the
cornerstone of the biological edifice. All that still remains open is the
question as to what forces and causes this remarkable development – evolution
– should be attributed.
There are three conflicting schools of thought here.
The vitalists believe in an extrasensory force which guides organisms toward
a higher state of perfection. The Lamarckians believe in the heritability
of acquired characteristics – a theory which would greatly facilitate our
understanding of evolution but has yet to be proven, and, indeed, has largely
been discredited. Finally, most present-day biologists espouse the mutation
theory, according to which the upward evolution of organisms has been effected
by random inherited changes. The role of the naturalselection process to
which Darwin drew attention is by no means confined to the last-named theory.
Rather, it has been a decisive factor in any speculation on the emergence
of new forms. However new animals or plants may have come into being, they
must in every case have had to contend with different and often vicissitudinous
living conditions. As a result, they managed to assert themselves only
when they equaled or surpassed their rivals' capacity for survival.
In view of the evidence assembled during the last 100
years, there can be no serious doubt that all higher animals and plants
are descended from unicellular organisms. We can now state, with a confidence
verging on certainty, that insects and spiders are descended from marine
arthropods; that existing terrestrial vertebrates evolved from fish; that
reptiles are descended from amphibians; that from reptiles there evolved
birds on the one hand and mammals on the other; and that man is descended
from two now-extinct branches of the large ape family. We are thus related
not only to apes but also to lizards, batrachians, fish, unicellular organisms
– yes, even to plants.
The Christian religion no longer adopts a hostile attitude
toward the theory of evolution. On the Roman Catholic side, the Pope himself
commented on the problem in 1950, in the
(original book page 19)
encyclica Humani generis. The Catholic Church now holds
that primeval man, being descended from the ape family, acquired his immortal
soul by divine afflatus in the Early Pleistocene period, or about 800,000
years ago. According to this doctrine, therefore, God made use of an existing
animal body and transformed it into man by an act of creation.
We have long grown accustomed to some of the consequences
which stem from our kinship with animals. For instance, few people find
it disturbing that numerous drugs are developed and tested by means of
experiments on animals. Since many of the hormones at work inside us are
the same as those in the more closely related animals, we extract them
from their glands and inject them, as required, into man. Examples are
the thyroid hormone, insulin, and the male sex hormone. Our knowledge of
the function of human muscles and human nerve cells is based on experiments
conducted principally with frogs, fish, and rodents. And our very advanced
knowledge of human heredity and of the complex structure of human hereditary
factors was gained predominantly from experiments with the pea (in other
words, a plant), the porpoise, and the fruit fly Drosophila. None of this
would be possible were it not for the existence of a genuine relationship.
Turning to the subject of human behavior – that is to
say, the reasons why we select this or that particular way of life, what
motives govern our various actions, and the way we react to given situations
– we find that this complex of problems still falls within the competency
of sciences which pay little or no heed to the fact of our evolution. The
main questions explored by philosophy, psychology, sociology, and other
sciences concerned with human behavior are rooted in conceptual systems
which developed in an age when man's descent from the animal kingdom was
still unknown. To them, man is not only a focus of observation but the
starting point of almost every discussion. Now that our origins are no
longer in doubt, however, it is only logical that man's behavior should
be seen against the background of our animal descent – that we should proceed
from the modest beginnings of a long chain rather than from its final link.
Only by asking what in our behavior still links us with
(original book page 20)
our animal past can we ascertain the nature of our peculiarity
– our differentness.
Human beings have shown themselves extremely skillful
at mastering their environment, and technological progress has brought
us a breathtaking accretion of power. No such enormous strides are demonstrable
in the field of intraspecific behavior, or human coexistence. As always,
humanity's progress is characterized by crime and war. As always, the individual
remains subject to highly mysterious whims and moods which all too often
prompt him to irrational conduct. As always, whole communities and races
are gripped by the most destructive passions. Here man is confronted by
peculiarities of temperament which are demonstrably rooted, not in his
intellect, but in far deeper "layers" of his nature. Human nature being
possibly or even probably the remains of an ancient heritage and explicable
only by reference to our descent, what could be more logical than to place
this heritage, this ancestry, in the forefront of our research – indeed,
to make it our point of departure? Is this not the best way of coping with
just these deeper layers in our nature, with just this mysterious nature
which dwells within us?
Konrad Lorenz, the founder of modern behavioral research
(ethology), pointed out years ago that knowledge obtained from the study
of animal behavior ought to be applied to the better understanding of human
behavior. He described this as "the most important practical task" confronting
this branch of research and has himself been responsible for numerous initiatives
in this direction. His words found little favor with students of the human
mind, however, and no reorientation toward this totally different point
of departure – which in practice begins with the smallest of all primitive
living creatures – has yet been undertaken.
American environmentalists, in particular, take the view
that practically all human behavior is acquired, and that man can therefore
be molded at will by upbringing and education. Animal behavior is likewise
attributed almost entirely to learning processes. The European schools
of behavioral research, particularly those of Lorenz and the Dutch zoologist
Tinbergen, have arrived at quite different conclusions. Exhaustive experi-
(original book page 21)
ments have shown that many elements in the behavior of
animals, even of the most closely related higher mammals, are fixed by
heredity. The results of this research suggest that human behavior is probably
more predetermined than we realize.
The following chapters are intended to present the major
results of behavioral research in as easily digestible a form as possible.
The aim is to show what basic biological conditions gave rise to the individual
phenomena and effects of animal behavior, from which human behavior evolved.