Hypnosis - Chapter 3
Everyone likes to think that no one can control what we think and how we react, how we see ourselves and the world around us, but that thinking is delusional in itself. A person is born almost like a blank slate all we become and how we behave results from a learning process, that is non-linear and hard to completely predict since biologic makeups also have a large impact. It is hard to consciously realize that we are subconsciously puppets of our own desires, our needs and wants.
In this section we will look on what is known about the processes that define, or can alter, our world view. Not all will deal directly with hypnosis but as we will see runs parallel to methodology, that exerts influence and shape individual realities and ultimately show that reality is a state of mind and that there are many techniques to change how our minds work, being hypnosis only one of them. That our belief systems may ultimately defines our reality.
Behavior: thoughts behind actions
So far neuroscience seems to point for the emergence of behavior from brain biology (genetics, structure and chemical interactions) that dictates the thought processes regarding sensorial experiences. But what seems to be still eluding are the patterns for the internal rationalization, that at times even seems to occur at a subconscious level. The brain seems to be more that what we account for as the self, or better yet, the self one is aware of, whom one identifies with.
Studies with twins shows that even a very close similitude of the biologic framework alone does not result in similar persons. An individual evolves in accordance the environment he grows in and that the inputs one receives (or is exposed to) are predominately more powerful for the process of defining oneself.
The Charles Whitman case is interesting for this topic, it all unfolded in Austin, Texas in the summer of 1966 at the Texas University clock tower that overlooks the campus. Charles, a student at the university and a former Marine climbed the tower and began randomly firing on the people bellow, killing 16 people and wounding more than 30 others, before being himself killed by the police. The police later found that hours before he also had killed his mother and stabbed his wife to death while she slept. The interesting part for this subject is that his actions were outside of his normal character, and that in his diary he progressively relates being having unexplainable angry and aggressive thoughts outside of his control, in his suicide note that he wrote the night before the shooting he requests for an autopsy to find out what was wrong with his brain. The autopsy performed later did in fact found a small tumor, probably a year old, the size of a small coin that was pressing on the Amygdala (region of the brain that deals with fear and aggression) that almost certainly explain the symptoms he described and was the driver for his behavior. So this case, among many others, demonstrates that changes that impact the biology of the brain will result in changes to its functions that can redefine behaviors outside the control of the conscious self. This has many ramifications even from a legal point of view, for instance in general terms the legal system punishments are mostly about reformation but how can that work if the problem is in the "hardware" not the "software". This can also be extrapolated to more complex pathologies, and even more confusing as for instance with psychopathy that has been proven results from combination of things including a specific brain abnormality, were it has also been determined that the self can override those biologic driven psychopathic limitations (reduced emotional emphasis on reflection).
So, to restate what we have discussed, behavior is at a lower level hard-wired into the biology of the brain, general to the species if we account for small deviations and major abnormalities, we can even generalize for gender and age if again we account for deviations. That more complex behavior is stacked into this framework and so in large part directed by it and so predictable to a degree. This of course is almost self evident, this reflection pattern based in our experiences is how we create our expectations when dealing with another sentient being and why we tend to anthropomorphize animals.
Therefore we are slowly de-constructing the erroneous belief that we have always conscious control of all our actions, that we behave the way we decide to. The reality is that who you are, how you act and what you think is largely determined by subconscious processes that you have no conscious control over. Some as we covered emerge from biology others result from learned automation the result of inferences by an always present subconscious brain. And this quasi autonomous brain has been active long before emergency of the self, a never ending process that starts at around age 3 and crystallizes after the hormonal chaos of puberty.
As an example, there was a study in the 60's by psychologist Hackard Hess, in that he created an experiment where he showed men pictures of women's faces and asked them to rate how attractive they where. Unaware to them half the pictures had the same women but their eyes had be dilated, so their pupils were bigger. The result was that all the men gave higher rates to the pictures with the feature even without knowing explicitly why, they did not conscious select for it. The belief is that it was because dilated pupils in women is a sign that indicate sexual readiness.
All this of course raises the question regarding free will. To what degree our decisions and actions are really dictated by the self?
Habits: patterns of expectation, plans for control
Habits and beliefs create patterns in the subconscious mind, dictating attitudes. They can be used to reinforce further the suggestions or be a good target for alteration, in fact they are by themselves nothing more than learned and strongly accepted suggestions that have become entrenched on the mind model of reality by the normal thought pattern and personal experiences, and ultimately shape our actions, decisions and establish one's value system.
To change or create an effective result, one must understand the causes and how it relates to the individual. Men as most, if not all animals, is pleasure guided. We avoid pain and seek pleasure, this is the root of cravings and addictions, the way each individual creates associations, the other side of the coin is the creation of phobias and aversions. This is the push-and-pull force that motivates and guides us, they are not equal to all persons. Biology, how the brain evolves neurological connections and uses experiences, and even the way each person stores memories of past events will determine what triggers behavior and habits. Those ultimately form a personal philosophy and how one faces decisions during the daily routines. Habits and behaviours are mostly automated optimizations of the brain to save time and effort in reaching the solution to problems, even if sometimes what is learned is not the optimal path. This is how a personal philosophy emerges and evolves along our lifetime.
A personal philosophy, that is, the sense of self and the understanding of how we comprehend and relate to reality is build on the foundations of what one knows and how one comes to know what one knows. These are the pillar that permit change and sustain beliefs, a weakness on the chain of facts that lead to a conclusion erode the validity of the conclusion as much as any blemish to the source of the knowledge. This is also why rapport is extremely important between the hypnotist and the subject, why suggestions are more powerful when used in consecutive degrees and compounded and even why a deeper hypnotic trance will have better results (since the critical aspect of the mind is more suppressed).
Instinct can be defined in general terms as a specific type of subconscious behavior, that guides basic emotional responses. In fact in psychology it was first used in the 1870s by Wilhelm Wundt but it is a characteristic that is commonly attributed to most animals behavior. In that respect instinct seems to supersede any analytical or critical thinking and seems guided by biological imperatives, like survival, subconscious fight or flight decisions, reproduction and first impressions.
From the middle of 20th century, the term and the study of instinctual behavior in relation to humans has mostly been replaced by behaviorism, nevertheless, people still recognize this type of behavior as distinct, referring to it sometimes as a gut feeling or a sixth sense. In any case it seems that humans are able to override or suppress most of this type of emotional response or motivational force (drive) if able to use critical thinking, failing to do so often results in performing actions outside of accepted behavior in society. A clear example of instinct behavior is the herd mentality that arises in a crowd that perceives immediate danger, often enough leading to unnecessary death or damage.
The book "Instinct" (1961) established a number of criteria which distinguishes instinctual responses from other kinds of behavior. It states that to be considered instinctual, a behavior must a) be automatic, b) be irresistible, c) occur at some point in development, d) be triggered by some event in the environment, e) occur in every member of the species, f) be unmodifiable, and g) govern behavior for which the organism needs no training (although the organism may profit from experience and to that degree the behavior is modifiable).
Today it is believed that dreams, among other things, serve the function of preemptively establishing responses to unpredictable situations, it is possible that they also have the purpose of serving as an outlet to suppressed instinctual responses or even as a way to model instinctual responses. In the case of hypnosis, akin to a guided dream state, instinct behavior can be redirected, and the override capacity improved, remembering however that instinctual responses can never be suppressed or removed from a conscious state. They can however be suppressed preemptively if the subject is in a state that prevents or delays the conscious mind from identifying the trigger.
Behaviorism is a school of psychology that takes the objective evidence of behavior and measured responses to stimuli. This is the only concern of its research and the only basis of its theory. Behaviorism does not take into consideration the concept of the unconscious mind, even if it can be argued that behavior to some level can be the result of a non-conscious decision. Behaviorism can be said to derive from the works in the areas of physiology and neurology, in temperament, conditioning and involuntary reflex actions by Ivan Petrovich Pavlov (Nobel Prize in Physiology or Medicine in 1904).
Behaviorism is important for hypnosis as it helps explain the reasons behind responses, and so it can be helpful in constructing better suggestions. Even permitting to create mental stimuli as to obtain the necessary reaction or changes in behavior.
- Social Activity
Humans are social animals, as such there are many instinctual drives that creates a need for social interaction. It is hard to define where instinct and learned behaviors begin but many of the assessments we do about other humans we contact starts at a automated subconscious level. The way one walks, gesticulates or smiles, especially facial expression, has an huge impact in establishing a sense of empathy and understanding that complements and can even supplant at an emotional level what can be gathered by conscious examination of evidence. This effects can even be exacerbated when amidst large groups. The wikibook Guide to Social Activity covers some of this topics more in depth.
Reflex vs Unconscious thought processes
When refereeing to reflex the meaning may differ, there is the physiological reflex, that is basically an involuntary and nearly instantaneous movement directed by the central nervous system (CNS) in response by to a stimulus, in some respects this seems to be highly related to instinct, but at a very basic level. Many of these types of reflexes are quite complex requiring a number of synapses in a number of different nuclei in the CNS (e.g., the escape reflex). Others reflexes in this category involve just a couple of synapses to function (eg., the withdrawal reflex), so it becomes clear that there is an overlap of complex physiological reflexes and the more basic instinctual behaviors, that we have covered earlier.
Processes such as breathing, digestion, and the maintenance of the heartbeat can also be regarded as reflex actions, according to some definitions of the term. With hypnosis some minor control can be exerted on some of these reflex action, by reinforcing the subconscious control it is possible to alter the rate of breath or heart rate, without making a conscious effort to do so.
The reflex and reaction time is extremely important for rapid and instant inductions in hypnosis, that depend on the startling factor to create a hypnotic state, this is a characteristic that is common also to other animals. Visual stimuli can be also important for subliminal messages and in determining rates of change for instance using visual methods of induction, and there is possibly a connection to the efficacy of other types of brain entrainment as binaural sound or other similar methodologies.
- Reflex arc
A reflex arc is the neural pathway that mediates a reflex action. In higher animals, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord. This characteristic allows reflex actions to occur relatively quickly by activating spinal motor neurons without the delay of routing signals through the brain, although the brain will receive sensory input while the reflex action occurs.
There are two types of reflex arc - autonomic reflex arc (affecting inner organs) and somatic reflex arc (affecting muscles).
“I am enough of an artist to draw freely upon my imagination. Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.”
– Albert Einstein.
While imagination can seem limitless, there is undoubtedly a relationship between what we can imagine and what we know. But the fact remains that the power or the capacity for imagining beyond the restrictions of what is a real possibility is one of the more important characteristics of the human mind, it not only permits us to supplant gaps on our knowledge but to aspire and go beyond what we define as our own limits.
Conditioning may have many different meanings, but all are part of behaviorism techniques that relate to creating in the subject a response (acceptance being one example). Classical conditioning, also referred to as Pavlovian or respondent conditioning, or even Pavlovian reinforcement, as we have already covered deals with reflexive and unconscious thought processes.
As seen before in regards to drivers of behavior, pleasure and pain seem to be the best tools to exercise conditioning, noting that one seeks pleasure and avoids pain. The model of reward system is clearly used openly over society (medals, prizes, etc) and with animals it is the preferred method, for example the dog that associates a clicker with food, or a lab rat that is given shocks as it performs a task.
The procedure for inducing classical conditioning typically involves presentations of the conditioned stimulus (CS) a neutral stimulus event that does not result in an overt behavioral response to the subject, along with a stimulus of some significance, the unconditioned stimulus (US) that triggers the unconditioned response (UR) that is often innate or reflexive but can also be a result of compounding the process.
Pavlov demonstrated that if the neutral stimulus is presented along with the unconditioned stimulus (US), it would become a conditioned stimulus (CS). Pavlov used the term conditioned because he wanted to emphasize that learning required a dependent or conditioned relationship between CS and US. If the CS and US always occur together and never alone, this perfect dependent relationship or pairing, causes the two stimuli to become associated and the organism produces a behavioral response to the CS. Pavlov called this the conditioned response (CR).
A perfect conditioned relationship is not necessary for conditioning but the strength of the CR progressively degrades as the conditioned relationship is weakened.
Types of classical conditioning:
- Forward conditioning: Learning is fastest in forward conditioning. During forward conditioning the onset of the CS precedes the onset of the US. Two common forms of forward conditioning are delay and trace conditioning.
- Delay conditioning: In delay conditioning the CS is presented and is overlapped by the presentation of the US.
- Trace conditioning: During trace conditioning the CS and US do not overlap. Instead, the CS is presented, a period of time is allowed to elapse during which no stimuli are presented, and then the US is presented. The stimulus-free period is called the trace interval. It may also be called the conditioning interval.
- Simultaneous conditioning: During simultaneous conditioning, the CS and US are presented and terminated at the same time.
- Backward conditioning: Backward conditioning occurs when a conditional stimulus immediately follows an unconditional stimulus. Unlike traditional conditioning models, in which the conditional stimulus precedes the unconditional stimulus, the conditional response tends to be inhibitory. This is because the conditional stimulus serves as a signal that the unconditional stimulus has ended, rather than a reliable method of predicting the future occurrence of the unconditional stimulus.
- Temporal conditioning: The US is presented at regularly timed intervals, and CR acquisition is dependent upon correct timing of the interval between US presentations. The background, or context, can serve as the CS in this example.
- Unpaired conditioning: The CS and US are not presented together. Usually they are presented as independent trials that are separated by a variable, or pseudo-random, interval. This procedure is used to study non-associative behavioral responses, such as sensitization.
- CS-alone extinction: The CS is presented in the absence of the US. This procedure is usually done after the CR has been acquired through "forward conditioning" training. Eventually, the CR frequency is reduced to pre-training levels. Essentially, the stimulus is presented until habituation occurs.
After conditioning, subjects that show the conditional response not just to the original conditional stimulus but also to new stimuli that resemble that stimulus are displaying what is called generalization.
Extinction and spontaneous recovery
Without the US, the newly learned CS elicits less and less UR on subsequent trials shows that it eventually becomes extinct as a behavior. Even with extinction, there was no clear evidence that the subject returned to its fully unconditioned state. The conditional reflex can be partially renewed after a certain time period has passed, a phenomenon known as spontaneous recovery. Pavlov concluded that the conditional reflex is not entirely lost during extinction, but possibly inhibited. In this state, the behavior can be recovered after the passage of time or the recurrence of the unconditional stimuli.
Latent inhibition to conditioning
This happens when a CS is presented several times before training pairing CS–US commences. The pre-exposure of the subject to the CS before paired training slows the rate of CR acquisition relative to subjects that are not CS pre-exposed.
Conditioned inhibition of conditioning
Three phases of conditioning are typically used:
- Phase 1
- A CS, defines now as CS+, is paired with a US until asymptotic CR levels are reached.
- Phase 2
- CS+/US trials are continued, but interspersed with trials on which the CS+ in compound with a second CS, but not with the US (i.e., CS+/CS trials). Typically, subjects show CRs on CS+/US trials, but suppress responding on CS+/CS trials.
- Retention test
- The CS is paired with the US. If conditioned inhibition has occurred, the rate of acquisition to CS should be impaired relative to organisms that did not experience Phase 2.
This form of classical conditioning involves two phases.
- Phase 1
- A CS, now defined as CS1, is paired with a US.
- Phase 2
- A compound CS (CS1 plus a new CS ) is paired with a US.
- Retention tests
- A separate test for each CS (CS1 and the newly introduced CS) is performed. The blocking effect is observed in a lack of conditional response to the new CS. This suggests that the first phase of training blocked the acquisition of the new CS.
Theories of conditioning
Stimulus–response (S–R) theory suggests that the a CS is associated with the US within the brain, without involving conscious thought. The second, stimulus–stimulus (S–S) theory, involves cognitive activity in which the CS is associated to the concept of the US, a subtle but important distinction.
S–S theory is a theoretical model of classical conditioning that suggests a cognitive component is required to understand classical conditioning, while S–R theory proposes that a cognitive component is merely at play. S–R theory suggests that an animal can learn to associate a CS with the impending arrival of the associated US, resulting in an observable behavior such as salivation. S–S theory suggests that the animal salivates to the bell because it is associated with the concept of the US, which is a very fine but important distinction.
It is hard to select one theory over the other, in what relates to hypnosis both models could apply but the stimulus–stimulus (S–S) theory seems more appealing, for instance in pain suppression you can puncture the skin of a subject without he/she feels any pain and even reduces bleeding but optimal results suggest that the subject must be informed of what is to happening and a high level of confidence in the hypnotist will have better results over self-hypnosis, this seems to indicate that it is not a simple association but a more complex concept and a higher cognitive activity takes place so that the distinction can occur. This is not to say that one system if more efficient that the other, it also will depend mostly on how the suggestions was made and how capable one is to perform self-hypnosis. But the fact that increasing the rapport of the subject over the experience makes it easier indicates that goes beyond a simpler response to the CS.
Anchoring is simply a label for the conditioning process- it occurs naturally meaning that triggers have already been learned. For instance, in a study on economics and the psychology of auction bidding. A group of people were required to write down the last numbers of their social security number next to their bid as a mean of identification. The results showed that those that had written an higher id. numbers also bidden higher. This among other evidences provides substantiation that some of our choices are influenced at a subconscious level by learned triggers.
Any meaningful information we receive will have a significance to our subconscious, be it a simple sound or word or a visual queue. We may not be aware of it but every time the trigger is detected, its neural connections are reinforced.
The term mind control is often used to characterize external control of the mind of others, of course to some degree there is an intersection with hypnosis and any other form of "mind control" since the objectives are similar. A distinct difference is that even if a trance state can be induced in a mass of people, it is extremely difficult to consistently exert complex control over that mass by means of hypnosis alone. Of course this limitation can be addressed by using a continued and repeated methodology...
"Wrightwood. Cal. 21 October, 1949
Dear Mr. Orwell,
It was very kind of you to tell your publishers to send me a copy of your book. It arrived as I was in the midst of a piece of work that required much reading and consulting of references; and since poor sight makes it necessary for me to ration my reading, I had to wait a long time before being able to embark on Nineteen Eighty-Four.
Agreeing with all that the critics have written of it, I need not tell you, yet once more, how fine and how profoundly important the book is. May I speak instead of the thing with which the book deals — the ultimate revolution? The first hints of a philosophy of the ultimate revolution — the revolution which lies beyond politics and economics, and which aims at total subversion of the individual's psychology and physiology — are to be found in the Marquis de Sade, who regarded himself as the continuator, the consummator, of Robespierre and Babeuf. The philosophy of the ruling minority in Nineteen Eighty-Four is a sadism which has been carried to its logical conclusion by going beyond sex and denying it. Whether in actual fact the policy of the boot-on-the-face can go on indefinitely seems doubtful. My own belief is that the ruling oligarchy will find less arduous and wasteful ways of governing and of satisfying its lust for power, and these ways will resemble those which I described in Brave New World. I have had occasion recently to look into the history of animal magnetism and hypnotism, and have been greatly struck by the way in which, for a hundred and fifty years, the world has refused to take serious cognizance of the discoveries of Mesmer, Braid, Esdaile, and the rest.
Partly because of the prevailing materialism and partly because of prevailing respectability, nineteenth-century philosophers and men of science were not willing to investigate the odder facts of psychology for practical men, such as politicians, soldiers and policemen, to apply in the field of government. Thanks to the voluntary ignorance of our fathers, the advent of the ultimate revolution was delayed for five or six generations. Another lucky accident was Freud's inability to hypnotize successfully and his consequent disparagement of hypnotism. This delayed the general application of hypnotism to psychiatry for at least forty years. But now psycho-analysis is being combined with hypnosis; and hypnosis has been made easy and indefinitely extensible through the use of barbiturates, which induce a hypnoid and suggestible state in even the most recalcitrant subjects.
Within the next generation I believe that the world's rulers will discover that infant conditioning and narco-hypnosis are more efficient, as instruments of government, than clubs and prisons, and that the lust for power can be just as completely satisfied by suggesting people into loving their servitude as by flogging and kicking them into obedience. In other words, I feel that the nightmare of Nineteen Eighty-Four is destined to modulate into the nightmare of a world having more resemblance to that which I imagined in Brave New World. The change will be brought about as a result of a felt need for increased efficiency. Meanwhile, of course, there may be a large scale biological and atomic war — in which case we shall have nightmares of other and scarcely imaginable kinds. Thank you once again for the book. Yours sincerely, Aldous Huxley
Society due to its intrinsic nature demands order, and so every society (including those of other animals) has to evolve methods and created possibilities to exert control over the psyche of masses. Rituals for instance have the property of self reenforcement, managing not only expectation but creating a mental ease that arises from predictability and create a resistance to deviation. All the next items would fall in what is common referred as cultural conditioning.
The term is closely linked to socialization; in common discourse, indoctrination is often associated with negative connotations, while socialization refers to cultural or educational learning or conditioning, even if they are intrinsically the same. As explained below, in the case of Sociology, this gray area is deliberately exploited in order to hide a radical socio-political agenda behind a facade of mainstream education.
Indoctrination may start before the individual has mastered language, and, as we have discussed early, children have a low capacity for critical thinking. As such it is used pejoratively, often in the context of political opinions, theology or religious dogma.
Indoctrination is often, and misleadingly so, distinguished from education by the proposal that while an indoctrinated person is expected not to question or critically examine the doctrine those that underwent an education process are required to do so. This distinction is extremely misleading since in many curricula, especially in today's industrialized in complex world, abstraction, lecture and dull memorization has largely substituted direct experience and practicality.
In practice there is always a certain level of non-rational indoctrination, usually seen as miseducative but invariably present. Most but not all cultural background, can be seen as part of an indoctrination process, especially when linked with externally induced (not self generated by personal experience) feelings or rationalizations, for instance instruction in the basic principles of science, in particular, can not properly be called indoctrination if not presented in any special emotional light, and specifically in science, the sense that the its fundamental principles call for critical self-evaluation, an unemotional and skeptical scrutiny of one's own ideas, a stance outside any doctrine.
Concepts learned by indoctrination can be extremely hard to alter, and in hypnosis this concepts can be leveraged to further promote the acceptance of suggestions if lined up with this concepts regarded as absolute truths or of special significance to that person. For instance the belief in god, angels, unicorns, ponies, etc.
Consider that the best subjects are those than come to accept hypnosis as a way to bypass the capacity to do critical thinking and that suggestions are only of value if they are accepted without conscious evaluation and deliberation. It then fallows that the continued practice of hypnosis (or hypnotic experiences) is in fact a case of indoctrination itself, not only on the practice but on the acceptance of suggestions. It is not by chance that hypnotic phenomena, and hypnosis as a tool, is often related with many other form of indoctrination as most of the techniques if not equal are very similar in nature.
Superstition is the simple belief in something without any external factual evidence (to the self). This of course represent also any religious belief, even if there it can get more complex, because some artifices can be created to empower the superstition. That allied with group-think and an indoctrination program makes religion one of the more common examples of mind control over individuals, for example in a cult like format, but then it becomes more than centered on the individual to become a mass control.
There is a multitude of methods to induce trance states, the initial state of any hypnotic work, as we will cover later on, from light, sound, movement, even the use of drugs. So hypnosis and closely related techniques are use consistently to exert and shape thoughts in others, even without direct consent from the subjects. This is used in pop music and videos, commercials and in movies (product placement, emotional linkage of audio input, etc).
As knowledge on how the mind works is expanded, it is a certainty that it will be explored to control and manipulate masses, this is something that becomes self evident from the history of hypnosis amidst the religious context. It is also evident in todays world how ideas, habits and opinions are created in the minds of others; in fact in a democratic society it becomes the prominent way to exert any control on the population since other forceful methods can be easily reported, traced and gather popular objection if used in large scale.
This of course has implications in how propaganda has been evolving. Manufacturing Consent: The Political Economy of the Mass Media (1988), by Edward S. Herman and Noam Chomsky clearly lays out the control the mainstream media has over contemporary thought, political opinion, and government policy.
- Politics, marketing and advertising
Mass media is used mostly as a tool for sensitization and habituation, part the conditioning process. As is well understood the majority of mass media products have very little informational content, they mostly cater exclusively to what appeals the masses, that is the seeking of pleasure.
Subliminal advertising, a particular case of subliminal stimuli can be stated to have been created by James Vicary, a market researcher, in 1957 when he inserted the words "Eat Popcorn" and "Drink Coca-Cola" into a movie to study the phenomena. It has yet to be proven as a valid process to create new ideas, even if it is banned by most broadcasting authorities. In a 1962 Advertising Age interview, Vicary admitted that the original study was "a gimmick" and that the amount of data was "too small to be meaningful". Of note is also the fact that Vicary pioneered the use of eye-blink analysis to obtain clues about subjects' levels of emotional tension when exposed to various stimuli and studied the phenomena of impulse buying and word association.
The basics of the concept are valid, as we saw in anchoring and we will cover also other examples later, like how simple words can have power in themselves. But as a way to create new ideas and the strength it may have to modify behavior is very debatable, and of course it all depends on the degree of exposition, that it, the definition of what subliminal means.
Humans as a social animal has evolved many strategies and capabilities to make coexistence with other less stressful and beneficial to the individual. This includes many behavioral and psychological adaptations, some shared with other animals, like the appeal to the similar and symmetry, the safety assurance given by a shared purpose, the innate ability to mirror and empathize with others. All this creates what we define as "herd mentality" and a default resistance to changes that depends of a communal perceptual tipping point to enable acceptance of innovation.
This capacity is also felt for instance in large crowds, concerts or shows especially if the focus and the emotional investment is in a shared goal. Even the most individualistic person will be swayed by this type of effect and persuasion.
One of the clear benefits is that humans when in a group delegate, even at an unconscious level, task specific responsibilities to other, especially in areas that are not pressing priorities or that depends in special expertize that is believed (consciously or unconsciously) to be lacking. We often delegate authority to perceived figures of authority without the necessary verification or show of capability, especially if a sense acceptance of that authority is prevalent in the group.