Suggestibility is the quality of being inclined to accept and act on the suggestions of others. One may fill in gaps in certain memories with false information given by another when recalling a scenario or moment. Suggestibility uses cues to distort recollection: when the subject has been persistently told something about a past event, his or her memory of the event conforms to the repeated message.
 A person experiencing intense emotions tends to be more receptive to ideas and therefore more suggestible. Generally, suggestibility decreases as age increases. However, psychologists have found that individual levels of self-esteem and assertiveness can make some people more suggestible than others; this finding led to the concept of a spectrum of suggestibility.
 Attempts to isolate a global trait of "suggestibility" have not been successful, due to an inability of the available testing procedures to distinguish measurable differences between the following distinct types of "suggestibility":
 Wagstaff's view is that, because "a true response to [a hypnotic] suggestion is not a response brought about at any stage by volition, but rather a true non-volitional response, [and] perhaps even brought about despite volition", the first category really embodies the true domain of hypnotic suggestibility.
 Self-report measures of suggestibility became available in 2004, and they made it possible to isolate and study the global trait.
 Suggestibility can be seen in people's day-to-day lives:
 However, suggestibility can also be seen in extremes, resulting in negative consequences:
 Hypnotic suggestibility is a trait-like, individual difference variable reflecting the general tendency to respond to hypnosis and hypnotic suggestions. Research with standardized measures of hypnotic suggestibility has demonstrated that there are substantial individual differences in this variable.
 The extent to which a subject may or may not be "suggestible" has significant ramifications in the scientific research of hypnosis and its associated phenomena. Most hypnotherapists and academics in this field of research work from the premise that hypnotic susceptibility or suggestibility — that is, the depth of hypnosis a given individual can achieve in a given context with a particular hypnotherapist and particular set of beliefs, expectations and instructions — is a factor in inducing useful hypnotic states.
 Dr. John Kappas (1925–2002) identified three different types of suggestibility in his lifetime that have improved hypnosis:
 Emotional suggestibility – A suggestible behavior characterized by a high degree of responsiveness to inferred suggestions that affect emotions and restrict physical body responses; usually associated with hypnoidal depth. Thus the emotional suggestible learns more by inference than by direct, literal suggestions.
 Physical suggestibility – A suggestible behavior characterized by a high degree of responsiveness to literal suggestions affecting the body, and restriction of emotional responses; usually associated with cataleptic stages or deeper.
 Intellectual suggestibility – The type of hypnotic suggestibility in which a subject fears being controlled by the operator and is constantly trying to analyze, reject or rationalize everything the operator says. With this type of subject the operator must give logical explanations for every suggestion and must allow the subject to feel that he is doing the hypnotizing himself.
 However, it is not clear or agreed what suggestibility (i.e., the factor on hypnosis) actually is. It is both the indisputable variable and the factor most difficult to measure or control.
 What has not been agreed on is whether suggestibility is:
 Conceptually, hypnotizability has always been defined as the increase in suggestibility produced by hypnosis. In practice, hypnotizability is measured as suggestibility following a hypnotic induction. The data indicates that these are different constructs. Although the induction of hypnosis increases suggestibility to a substantial degree, the correlation between hypnotic and non-hypnotic suggestibility approximates the reliability coefficients of so-called hypnotizability scales. This indicates that hypnotic susceptibility scales are better measures of waking suggestibility than they are of hypnotizability.
 Existing research into the phenomena of hypnosis is extensive and randomized controlled trials predominantly support the efficacy and legitimacy of hypnotherapy, but without a clearly defined concept of the entity or aspect being studied, the level an individual is objectively "suggestible" cannot be measured empirically, and makes exact therapeutic outcomes impossible to forecast.
 Moreover, it logically hinders the development of non-bespoke hypnotherapy protocol. On this latter point, it must be pointed out that while some persuasion methods are more universally effective than others, the most reliably effective method with individuals is to personalize the approach by first examining clients' motivational, learning, behavioral, and emotional styles, among others. Indeed, few hypnotherapists will not make taking case history from the clients they will be working with priority.[citation needed]
 The intrigue of differences in individual suggestibility even crops up in the early Greek philosophers. Aristotle had an unconcerned approach:
 "The most intelligent minds are those that can entertain an idea without necessarily believing it." 
 This perhaps is a more accurate echo of the experience of practicing hypnotherapists and hypnotists. When anyone is absorbed in someone else's inspiring words as they outline an idea or way of thinking, the subjective attention is held because of the logic, the aesthetic, and the relevance of the words to one's own personal experience and motivations. In these natural trance states, like those orchestrated purposefully by a hypnotherapist, the 'critical faculties' are naturally less active when there is less to be naturally critical of.
 It is perhaps the "necessarily believing it" that is problematic, as this conception of suggestibility raises issues of the autonomy of attributing belief to an introduced idea, and how this happens.[clarification needed]
 Popular media and layman's articles occasionally use the terms "suggestible" and "susceptible" interchangeably, with reference to the extent to which a given individual responds to incoming suggestions from another. The two terms are not synonymous, however, as the latter term carries inherent negative bias absent from the neutral psychological factor described by "suggestibility".
 In scientific research and academic literature on hypnosis and hypnotherapy, the term "suggestibility" describes a neutral psychological and possibly physiological state or phenomena. This is distinct from the culturally biased common parlance of the term "suggestible". The term "susceptible" implies weakness or some increased danger to which one is more likely to become a victim. It therefore has a negative effect on expectation and itself is a hypnotic suggestion that suggestions must be noticed and guarded against.  Both terms are often bound with undeserved negative social connotations not inherent in the word meanings themselves.
 To be suggestible is not to be gullible. The latter pertains to an empirical objective fact that can be shown accurate or inaccurate to any observer; the former term does not. To be open to suggestion has no bearing on the accuracy of any incoming suggestions, nor whether such an objective accuracy is possible, as is the case with metaphysical belief.
 Some therapists may examine worries or objections to suggestibility before proceeding with therapy: this is because some believe there is a rational or learned deliberate will to hold a belief, even in the case of more convincing new ideas, when there is a compelling cognitive reason not to 'allow oneself' to be persuaded. Perhaps this can be seen in historical cases of mass hypnosis where also there has been media suppression. In the individual, unexamined actions are sometimes described by hypno- and psycho-therapists based on outgrown belief systems.
 Hypnotic suggestions include terms, phrases, or whole concepts where to understand the concept includes making sense of a subjective sensation, or a framework for the appropriate response.... simple one-word forms of this include the word terrorism where to understand the concept, one must understand the notion of terror and then understand in the sentence that it is meant to refer to "that" given object.
 Cognition of a phrase must occur before the decision how to act next can occur: because the concepts must exist before the mind. Either they are suggested from the mind itself, or in response to introduced suggestions of concepts from outside – the world and its scenarios and facts, or suggestions from other people.
 A suggestion may direct the thoughts to notice a new concept, focus on a specific area within the world, offer new perspectives that later may influence action-choices, offer triggers for automatic behavior (such as returning a smile), or indicate specific action types. In hypnotherapy the portrayed realistic experience of the client's requested outcome is suggested with flattery or urgency, as well as personalized to the client's own motivations, drives, and tastes.
 Suggestions are not necessarily verbal, spoken, or read. A smile, a glare, a wink, a three-piece suit, a scientist's white coat, are all suggestive devices that imply more than the immediate action. A hypnotist uses techniques that use these instinctive "fillings-in of gaps" and changes to how we respond to a scenario or moment. In the therapy setting, a hypnotist or hypnotherapist will likely evaluate these automatic cognitive leaps, or dogma, or any self-limiting or self-sabotaging beliefs.
 Being under the influence of suggestion can be characterized as exhibiting behavioral compliance without private acceptance or belief.
That is, actions being inconsistent with one's own volition and belief system and natural unhindered action-motivations. This could hinder the autonomy, expression or self-determination of an individual. It could equally supersede emotions with rationally chosen, deliberate long-term results.
 The applications of hypnosis vary widely and investigation of responses to suggestion can be usefully separated into two non-exclusive broad divisions:
 According to some theoretical explanations of hypnotic responses, such as the role-playing theory of Nicholas Spanos, hypnotic subjects do not actually enter a different psychological or physiological state; but, rather, simply acting on social pressure – and, therefore, it is easier for them to comply than to disobey. Whilst this view does not dispute that hypnotized individuals truly experience the suggested effects, it asserts that the mechanism this takes place by has, in part, been "socially constructed" and does not, therefore, require any explanation involving any sort of an "altered state of consciousness".
 Children have a developing mind that is constantly being filled with new information from sources all around them. This predisposes children towards higher levels of suggestibility, and as such children are an important area of suggestibility investigation. Researchers have identified key factors, both internal and external, that are strong markers for suggestibility in children.
 In extreme events such as sexual abuse, extreme anxiety or mistreatment, children can in fact be greatly subjected to suggestibility. It is possible that a child may recall something that didn't actually happen or they are so traumatized that they do not want to think about what actually happened.
 Little research has been carried out into the effects of anxious mood at the time of either the encoding of misleading post‐event information or the time of its possible retrieval, on subsequent suggestibility. Memory accuracy for non‐suggestible items was unaffected by the anxious mood induction. With respect to suggestibility, there was a strong effect of misleading information. This is just one example of how a highly emotional situation such as an anxiety attack can create suggestibility misconception.
 Another example of research is that memory, suggestibility, stress arousal, and trauma-related psychopathology were examined in 328 3- to 16-year-olds involved in forensic investigations of abuse and neglect. Children's memory and suggestibility were assessed for a medical examination and venipuncture. Being older and scoring higher in cognitive functioning were related to fewer inaccuracies. In addition, cortisol level and trauma symptoms in children who reported more dissociative tendencies were associated with increased memory error. This again proves how a stressful or traumatic experience in young children can be affected by suggestibility.
 It is claimed that sufferers of post-traumatic stress disorder and dissociative identity disorder (DID) are particularly suggestible. While it is true that DID sufferers tend to score to the higher end of the hypnotizability scale, there have not been enough studies done to support the claim of increased suggestibility.
 Aspects of crowd dynamics and mob behavior, as well as the phenomenon of groupthink are further examples of suggestibility.[citation needed]
 Common examples of suggestible behavior in everyday life include "contagious yawning" (multiple people begin to yawn after observing a person yawning) and the medical student syndrome (a person begins to experience symptoms of an illness after reading or hearing about it). Placebo response is also thought to be based on individual differences in suggestibility, at least in part. Suggestible individuals may be more responsive to various forms of alternative health practices that seem to rely upon patient belief in the intervention more than on any known mechanism. Studies of effects of health interventions can be enhanced by controlling for individual differences in suggestibility. A search of the Mental Measurements Yearbook shows no extant psychological test for this personality characteristic. The Gudjonsson suggestibility scale is questionable for this kind of purpose due to its narrow focus. In addition to health-related implications, persons who are highly suggestible may be prone to making poor judgments because they did not process suggestions critically and falling prey to emotion-based advertising.