1. Description of the obstacle
It is now time to acknowledge that the scientific specificity
of physiological psychology separates it from the rest of psychology.
Although some psychologists would like to overcome the differences
and reunite the science of psychology, most of us realize that
this goal is not only impossible but also undesirable. The old
ideal of unified knowledge has long been abandoned in the practice
of modern science (Bachelard 1934, Kuhn 1962, Refinetti 1983).
Instead of a coherent, integrated body of knowledge, what we
have today is a dispersion of sciences that are only partially
related to each other (Refinetti 1989).
Once we accept the fact that physiological psychology is irreconcilably
separated from at least some of the remaining forms of psychological
science, it is not difficult to realize that general psychology
may be an epistemological obstacle to the advancement of physiological
psychology. This was indirectly mentioned in Chapter 6, where
the mentalist (or behaviorist) nature of some forms of psychology
was described as an obstacle to physiological psychology. In
the present Chapter, three new obstacles that emanate from psychology
will be described, namely: bidimensionalism, innatism, and environmentalism.
Bidimensionalism refers to the idea that some phenomena are
bidimensional, that is, have two distinct dimensions of being.
This bidimensionality takes place in the temporal sphere (thus
generating the past-present dichotomy) as well as in a topological
sphere (thus generating the endogenous-exogenous dichotomy).
Let's examine these concepts in a little more detail.
The endogenous-exogenous dichotomy refers to causal mechanisms
as they relate to the organism, and is closely related to an
obstacle previously studied (viz., psychophysical complementarism).
A typical explanation in psychology indicates the fact that
a strongly emotional event may lead to psychological distress
and eventual neurotic symptoms. Although the neurotic symptoms
may affect bodily functions (e.g., hysteric immobilization),
they are determined by psychodynamic mechanisms. This means
that an exogenous event (the emotional situation) is assimilated
as an endogenous element in the physiology of the body and can
affect the operation of several organs. For the behavioral
neuroscientist (i.e., the physiological psychologist), organisms
are topologically unidimensional. This means that, when a stimulus
is presented to an organism, what "enters" the organism is not
an image of the proximal stimulus but the nervous impulses generated
at the sensory receptors. Inside the organism, everything has
a single dimension: the neural dimension. Psychologists, as
we just saw, often endorse the endogenous-exogenous dichotomy
and argue that an exogenous stimulus can simply migrate into
the organism. Thus, when the proximal stimulus is a "traumatic
experience", the psychologist claims that this stimulus somehow
enters the body and can lead to psychological disorders and mental
illness. For the behavioral neuroscientist, a traumatic experience
must have a neural correlate which enters the body as a series
of action potentials. That is, the exogenous stimulus is always
translated into endogenous activity. Consequently, when a psychologist
shows that some form of mental illness results from a psychological
conflict, he is not describing the etiology of the disease; rather,
he is obstructing the study of what causes the disease.
In a similar way, the psychosomatic physician claims that a
situation of psychological tension enters the body and eventually
reaches the stomach to produce ulcers. For the neuroscientist,
however, psychological tension is a condition of the central
nervous system developed by a series of nervous inputs, and it
is this condition of the nervous system that leads to nervous
stimulation of the stomach to produce ulcers. As Le Grand noticed
wisely, phenomena of a physical dimension and phenomena of a
mental dimension cannot coexist inside the same organism (Le
The temporal form of bidimensionalism is similar to the topological
form. While making an analogy between the nervous system and
a computer, G. C. Quarton described well the behavioral neuroscientist's
view. According to him, past input and present input, as well
as programming instructions, are codified together in one single
language that controls the machine (Quarton 1967). That is,
organisms are temporally unidimensional and have their past experiences
incorporated in their nervous systems. On the other hand, psychologists
often endorse the past-present dichotomy and claim that the past
may come back to haunt a patient. For the psychologist, the
remembrance of past incidents may unleash mental disorder. For
the behavioral neuroscientist, the only way the past can haunt
an organism is if the sensory inputs from the past episode were
stored in the nervous system and can now be used to alter the
current functioning of the brain.
Innatism, the second obstacle, is the opposite of the third
obstacle, environmentalism. Needless to say, innatism is the
conception that all important behavioral characteristics of an
organism are genetically inherited and do not change appreciably
as a result of experience. Environmentalism is the conception
that all important behavioral characteristics of an organism
are determined by experiencing the environment. Although many
psychologists would defend one of these conceptions, behavioral
neuroscientists believe that both innate disposition and environmental
stimulation are essential for the causation of behavior (e.g.,
Hebb 1949, Kandel 1976, Piaget 1970). For the behavioral neuroscientist,
the nature-nurture dichotomy is a fallacy.
2. Examples of the obstacles
Joseph Wortis (1967) provided us with a good example of bidimensionality
when he described what he considers to be two types of mental
retardation: the biological type and the non-biological type.
The causes of non-biological retardation would be poverty, psycho-social
deprivation, frustration, etc. Now, how can these factors affect
the functioning of the brain? They certainly cannot cross the
skull and attack neurons. If poverty, for instance, is a cause
of mental retardation, it is not so as "poverty" but as damage
to neurons and glial cells resulting from inadequate nutrition,
lack of environmental stimulation, etc. Non-biological types
of retardation cannot exist. To insist on their existence is
to support the endogenous-exogenous dichotomy and, therefore,
to obstruct the progress of behavioral neuroscience.
Innatism has traditionally been associated with ethology (e.g.,
Eibl-Eibesfeldt 1970, Ewer 1968). As Lorenz acknowledged, many
ethologists believe that the machinery of behavior houses a considerable
number of self-contained units that are refractory to learning
(Lorenz 1966 [p.102]). More recently, the creation of sociobiology
led to the development of even bolder innatist theories. For
instance, Hamilton's (1975) claim that racial discrimination
rests on direct genetic foundations is much more a reiteration
of the innatist credo than an inference based on actual scientific
research. It may be true that civil rights activists have repeatedly
made unfounded claims in the opposite direction, but this is
no excuse for a scientist to put scientific objectivity aside.
Any form of radical innatism is obstructive, as it places an
a priori principle above empirical research. No doubt we inherit
innumerable characteristics from our parents. But many characteristics
have to be learned, and it is only through investigation that
we can know which ones have to be learned. To give only one
example, research shows that infants are born with an equipotentiality
for the perception of musical scales and that acculturation is
responsible for the development of perceptual preferences (Lynch
et al 1990).
Environmentalism has been traditionally associated with behaviorism.
John Watson's (1925) claim that learning alone could determine
whether any given child would become a successful business person
or a beggar was as much a declaration of the environmentalist
credo as an unfounded statement about the power of behavioral
sciences. Skinner's (1972) claim that most behaviors are developed
by operant conditioning is again only the reiteration of a credo.
Orthodox behaviorists seemed to disregard the fact that the
ability to learn is itself inherited.
Although not traditionally recognized as such, the culturalist
school has also been a supporter of environmentalist beliefs.
Cultural anthropologists, such as Ruth Benedict (1934), and
sociologists, such as Emile Durkheim (1907) and Max Weber (1958),
insisted on the importance of cultural (i.e., environmental)
factors in the production of ordinary behaviors, new ideas, and
economic policies. A recent example is Ruth Bleier's criticism
of extreme innatism, where she defends an equally repugnant environmentalism:
"Distinctions of human characteristics and temperaments into
innate male and female natures have been social, cultural constructs
and are not natural. They are part of an ideology that attempts
to make what are in fact social and political distinctions appear
to be natural and biological ..." (Bleier 1984 [p.7]). At the
present state of our knowledge, Bleier's statement is just as
unfounded as her opposer's. If anything, we would expect both
an innate and an environmental component to exist. Statements
that strongly favor either one of these components are espistemological
obstacles to physiological psychology.
This Chapter has described bidimensionalism, innatism, and environmentalism
as obstacles to the development of physiological psychology.
Although this situation is claimed to result from a rupture
between behavioral neuroscience and other areas of psychological
research, it should be remembered that no claim of scientific
superiority of behavioral neuroscience is being made. Even in
cases where such a claim could be made (e.g., when the scientificity
of behavioral neuroscience is contrasted with the uncertainty
of parapsychology), it should not be forgotten that the universe
of legitimate human intellectual activity is much broader than
the domain of immediately- or ultimately-useful scientific research.
Professor Michael Menaker, in whose laboratory at the University
of Virginia I had the honor to work during the year of 1990,
used to say that biological research is fundamentally an intellectual
enterprise comparable to poetry, music, and visual arts. It
would be mere hypocrisy to dismiss non-applicable scientific
research as worthless research. It would be equally hypocritical
to dismiss non-scientific activities as worthless activities.