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Two competing psychological branches are mentalism vs behaviorism. These co-developing branches of psychology have different ways of studying rational human behavior, cognition, and feelings. While adherents to these theories tend to compete, they are not mutually exclusive explanations for human decision-making and behavior.

Mentalism uses introspective analysis to understand human thoughts, perceptions, and feelings. The content of mind is true existence. Behaviorism is a reduction of human cognition and behavior to that which can be studied and categorized by empirical data, typified by stimulus-response data.

Mentalists believe in the whole being, with the mental component of ideas, thoughts, and feelings being as valid as physical actions. Behaviorists acknowledge feelings, but  dismiss the idea that actions have any real rational explanation beyond neurological impulses and reflexes based on behavioral training by external stimuli.

The Principles of Mentalism

The study of mentalism has often been equated to parlor tricks and illusion magic. This type of mentalism emphasizes the illusion of mind over matter. The idea that mental power can be used to influence physical surroundings. However, this is not the origin of mentalism and these ideas are not tenets of psychological mentalism.

Rather, mentalism in the study of psychology seeks to explain causes for human thoughts and behavior in a way that respects and explores our shared experiences of thoughts, dreams, feelings, and beliefs.

  • Classical mentalism is introspective. It seeks to understand the mind using the mind rather than chemical explanations or experimental processes.
  • Mentalism seeks to understand the nature of consciousness and the relation between individual consciousness and group consciousness.
  • Mentalism aims to identify the realities of intangible group awareness aside from physical conditioning. This would be more in the realm of finding the first cause of consciousness that results in physical conditioning practices.
  • Mentalism aims to understand both individual and shared perceptions. This particular study is often in direct contrast with behaviorism. Much of the support and progress of psychological mentalism in the 20th century was a reaction to the attempt to dismantle it by concurrently developing behaviorists.
  • Mentalism is concerned with the nature of mental imagery and the origins of mental imagery. Do mental images and ethereal ideas exist in reality in the universe and are then discovered with the mind? Mentalists believe that they do.
  • Mentalists believe that ideas, dreams, feelings, and thoughts have a concrete existence in the universe that is valid although intangible. 
  • Mentalists are more likely to approach a human as a “whole person,” believing that each individual is capable of real mental expression that is unique. Further, each person is capable of individual expression that is unaccountable by simple conditioning or neurological pathway stimulation.
  • Mentalists would argue that society is made of people, rather than people being made by society. That without individuals there is no society, therefore society as an intangible can not be blamed for all of the ills of the individual. 
  • At its most radical, mentalists claim that everything in existence is simply a state of mind. It is this radical mentalism that caused a rise in behaviorism which sought to dismantle this idea that all that exists is a projection of the mind. 

The Principles of Behaviorism

Behavioralism in general is a psychological study that aims to take the mystique away from human behavior. The psychological approach of behaviorism is a reaction to more radical forms of mentalism that claim that all things that we perceive as existing are simply entities in the mind. Behaviorists approach human rationality from a more concrete and empirical standpoint.

Behaviorists believed that the human mind can be understood best from the outside looking in, rather than using the mind to interpret itself. They felt that in order to properly understand the intricate workings of the mind, it must be viewed scientifically and tested empirically. Ideally, they hoped to eliminate all forms of bias, impression, ideation, and feelings from the scientific data about human behavior.

  • Classical behaviorism began with Pavlov’s research on training dog behavior. This research showed that an animal can be trained to anticipate reward by associating the reward with a preliminary stimulus.
  • Behaviorism was the predominant psychological theory during the first few decades of the 20th century.
  • Behaviorism as a formal study was pioneered by John B. Watson in an attempt to divorce the human mind from what he saw as undue religious influences on the human experience. He wanted to study human cognition without allowing for the concept of a human soul or inner consciousness.
  • Behaviorism is seen as an extension of the natural sciences. This is because it eliminates the introspection from psychology and places experimentation, theory, and analysis outside of the mind and into empirical data.
  • Behaviorism is only interested in measurable, observable data that can be gathered from human actions. 
  • Behaviorism seeks to produce evidence of the predictability of human activity based on reproduced studies.
  • Behaviorist researchers tend to do studies on animals because of the ethical concerns around behavioral training on human beings. The results of these studies are then applied to humans with the assumption that the human mind is on some level equatable to the animal mind.
  • Behaviorism reduces human thought, feeling, creativity, perception, and ideology to conditions imposed from without called conditioning. This conditioning can come from family, school training, religion, media, or society at large. 
  • Behaviorism believes that a human personality is formed by what is imposed on him from these sources of conditioning. 
  • Behaviorism acknowledges that humans do have feelings, but credits feelings, dreams, thoughts, and ideas to purely physiological phenomena.
  • This empirical science reduces human cognition to the conditioning of brain synapses. When an input is received there is a myriad of possible combinations of brain synapses that may fire. The brain is trained to follow certain synapse pathways by conditioning through reward and punishment.
  • Behaviorism has become a popular way of viewing humanity. This is convenient for many because it eliminates the need to understand the human consciousness and emotions. They can be ignored as chemical imbalances or the result of negative stimulus training.
  • The result of behavioral experiments in conditioning are imposed on the understanding of the entire human person and all actions taken by that person. This approach ignores the differences between a human and a rat that can not be quantified with empirical data.

Behaviorism Vs. Mentalism

Both views have dramatically different implications for understanding humanity and practicing individual therapy. Mentalism will seek to understand a person’s mind by delving deeper into the mind, but patients may find that they are becoming further lost into the web of their feelings, ideas, and perceived reality. This can make it very difficult for both patients and doctors to come to terms with the origins of mental distress.

  • The mentalist approach has taken big strides in recent decades as the cognitive sciences are now able to use brain mapping and the field of neuroscience advances rapidly, showing how external stimuli can activate parts of the physical brain. 
  • This shows promise in both validating human perceptions and individual identity while helping to understand how the brain is physically wired to cope with and incorporate external stimuli. 
  • Mentalism is concerned with why a person’s brain reacts a certain way when a difficult topic is mentioned or a specific memory is triggered.

Conversely, the behaviorist approach explains all human interactions and perceptions as a result of external stimuli and conditioned responses to them. In this type of therapy, behavioral psychologists try to pinpoint external stimuli that cause various conditioned responses that cause the patient to feel distressed.

  • This approach aims to relieve feelings of guilt and personal responsibility so that the patient can feel more comfortable and mentally stable.
  • Behaviorism can also benefit from new cognitive mapping discoveries, showing that stimuli can cause repeatable and reliable activation in certain brain areas. This is seen as a reinforcement that the human experience is simply a series of predictable responses to controlled stimuli.


Behaviorism explains human cognition and perception in terms of stimuli-response conditioning. Behaviorists acknowledge human emotion, but do not feel the need to explain it as more than predictable biological responses to stimuli. Mentalism theory explains human cognition and perception by introspectively exploring the inner workings of the human mind but often fails to give credit to the fact that humans are quickly and effectively conditioned.

Neither field of psychological science can stand alone and should be viewed symbiotically. In order to understand the human as a whole sentient being, we must take into account that humans are capable of concrete and unique feelings, ideas, and perceptions that can be conditioned to react to external stimuli using both reward and punishment.