Personalised Perception: The Effect of Personality on the Sensory Effects of Psychedelics

Psychedelics are known to produce highly variable changes in perception, including visual, auditory, tactile, olfactory, and gustatory distortions. The paper notes that while these substances are increasingly studied for therapeutic potential, the acute experience remains difficult to predict. Earlier research has suggested that extra-pharmacological factors such as set and setting matter, and that personality may shape some subjective aspects of the psychedelic state, but it is still unclear which personality traits are linked to which specific sensory effects. There is also disagreement in the literature about how important sensory phenomena themselves are for therapeutic outcomes, which strengthens the case for studying what predicts their intensity. Boardman and colleagues set out to examine whether personality traits are associated with the intensity of a range of sensory distortions during the acute psychedelic state. Their main aim was to test correlations between five-factor personality traits and trait absorption, on the one hand, and the reported intensity of 20 different sensory effects, on the other. The study was exploratory, but the authors hypothesised that personality variables would show significant associations with at least some of these sensory features and would help predict their intensity. The paper is framed as a survey-based study of psychedelic users in Aotearoa New Zealand, with an emphasis on whether personality testing might eventually help anticipate acute responses to psychedelics.

The researchers conducted an anonymous online survey approved by the University of Otago Human Ethics Committee. Data were collected between 25 April 2023 and 21 September 2023 using REDCap. Participants were recruited through flyers in Ōtepoti/Dunedin and advertisements on social media and online forums. Eligibility required participants to be at least 18 years old, fluent in English, resident in Aotearoa for at least 1 year, and to have used at least one listed psychedelic in Aotearoa, including DMT, LSD, psilocybin, mescaline, salvia divinorum, or a 2C-family drug. The survey covered demographics, drug-use patterns, personality, and previous psychedelic experiences. Personality was measured using the 60-item IPIP-NEO-60 for the Big Five traits and the 34-item Tellegen Absorption Scale, which assesses sensitivity to altered states, vivid imagery, and related experiences. The outcome set for this article consisted of 20 sensory features of psychedelic experiences, such as visual trails, breathing objects, colour enhancement, auditory or tactile hallucinations, out-of-body experiences, and synaesthesia. Participants were asked about either their most intense psychedelic experience or their typical experience, depending on how experienced they were. Those with four or more psychedelic experiences reported typical intensity, whereas those with fewer than four reported intensity during their most intense experience. The study also collected information on typical and intense doses, which were coded into five levels from microdose to very high dose using reference information and assumptions where needed. Responses that could not be coded were removed. Of 770 initial respondents, 426 remained for the correlation analyses. Because some participants had inadequate dosage data, the regression analyses were limited to 327 participants. The authors used Spearman’s correlation analyses and stepwise linear regression models in SPSS 27. The regression models included age, sex, social setting, physical setting, typical dosage, intense dosage, trait absorption, and the five Big Five domains. The goal was to identify which personality variables predicted the intensity of each sensory feature after accounting for setting and dose.

The final sample for the correlational analyses comprised 426 participants, with a near-even split between men and women and a mean age of 29.66 years. Most participants identified as White/European, and the most commonly reported typical psychedelic context was with a small group of close friends, usually at home or in another home, with outdoor or nature settings also common. In terms of experience frequency, the sample included a mix of relatively inexperienced and more frequent users. In the correlation analyses, trait absorption was the most consistently related personality variable. It was significantly associated with the intensity of all sensory features except psychoses and disgusting visuals. Several correlations were moderate or near-moderate in size, including field-of-vision changes (r = 0.300), visual acuity enhancement (r = 0.348), experiences of other worlds or dimensions (r = 0.315), and synaesthesia (r = 0.332). Other relatively strong associations for absorption included out-of-body experiences, beautiful visuals, and olfactory hallucinations. Among the Big Five traits, extraversion showed the clearest pattern of associations, although these were still weak overall, with correlations for gustatory hallucinations, beautiful visuals, and colour enhancement. Openness had only a few small associations, including a positive link with beautiful visuals and tactile hallucinations and a slight negative association with psychoses. Neuroticism, agreeableness, and conscientiousness each showed only a small number of weak correlations, with conscientiousness negatively related to disgusting visuals and positively related to colour enhancement. In the regression analyses, nine sensory features were significantly predicted by models that included personality variables. Social setting, physical setting, and dosage appeared to be stronger predictors than personality overall. Physical settings at festivals were strongly associated with greater intensity of experiences of other worlds or dimensions, and being at a festival also predicted that feature in the regression models. The text also reports that social setting was significantly predictive of reduced intensity of objects breathing and beautiful visuals compared with being at home. Trait absorption contributed small but significant predictive value in all nine of the reported models. Extraversion appeared in three of the nine models, and agreeableness in one. Neuroticism and conscientiousness did not add unique predictive value for the relevant outcomes. The authors emphasise that the beta estimates for personality variables were relatively low compared with those for setting and dosage. Overall, the results suggest that personality is associated with how intensely some sensory psychedelic effects are experienced, but the associations were modest rather than large.

Boardman and colleagues interpret the findings as evidence that personality traits are linked to the intensity of several sensory features during the acute psychedelic state, particularly trait absorption. They note that nearly all of the 20 sensory features correlated with at least one personality variable, and that nine features were predicted by regression models that included personality, although the explained variance was limited. In their view, absorption stands out as the most robust personality-related predictor, supporting earlier research suggesting that absorption is associated with sensitivity to altered states, vivid imagery, and stronger psychedelic experiences more generally. The authors regard the Big Five findings as less consistent and less definitive. They say the lack of stronger effects for openness was somewhat surprising given earlier research, and suggest that openness may be more relevant to cognitive and emotional aspects of the psychedelic experience, such as mystical experiences, than to sensory distortions. Extraversion showed some associations, including the strongest Big Five correlations in the study, but the pattern was not fully aligned with earlier work. Neuroticism was largely not predictive, apart from a small association with disgusting visuals, which the authors relate cautiously to earlier findings on challenging experiences. Agreeableness and conscientiousness were only weakly related to outcomes, and the conscientiousness finding for disgusting visuals was described as seemingly inconsistent with personality theory. The authors stress that the direct effects of personality were small compared with other factors such as social setting, physical setting, and dosage. They argue that personality may function more as a moderator than a direct cause, influencing choices about setting, dose, and harm-reduction behaviour rather than directly determining the experience. They also highlight several limitations: the study relied on retrospective self-report, which may be affected by recall bias, acquiescence bias, and sampling bias; detailed mental health diagnoses were not collected; some sensory items had obvious emotional valence, which may have influenced responses; dose coding relied on assumptions that may have reduced accuracy; important variables such as route of administration, pre-experience mood, and motivations were not measured; and the loss of data from those with more than 100 psychedelic occasions may limit generalisability. Despite these limitations, the authors suggest that personality measures, especially absorption, could be useful in future prediction tools aimed at anticipating acute reactions to psychedelics and thereby helping to minimise risks and maximise therapeutic benefits.

what this research adds to the literatur 14:01 This study adds to a small body of research on how individual differences shape the psychedelic experience, showing that personality traits, especially absorption, are linked to how intensely people feel sensory effects, but only modestly. Its main contribution is the finding that setting and dose matter far more than personality, which tempers the idea that a personality test alone could predict how someone will respond.