By: Fabiano de Abreu Agrela Rodrigues – Post-PhD in Neuroscience, Specialist in Behavioral Genomics and Intelligence
Throughout history, the concept of “normal” has been shaped by social conventions and statistical metrics. However, neuroscience confronts this term with a disturbing fact: epidemiological estimates suggest that approximately 30% to 50% of the global population may experience some diagnosable mental disorder over the course of their lifetime. This percentage increases when we include subclinical conditions and personality disorders, especially those in cluster B, such as narcissistic, histrionic, and borderline personality disorders, which, by their very nature, have low rates of self-recognition and diagnosis.
Considering that these individuals rarely receive professional evaluation, the epidemiological picture becomes even more distorted. The question, therefore, is inevitable: in a scenario where almost half the population could meet the criteria for some disorder, what would be the standard for calling someone “normal”?
In scientific logic, “normal” should be defined by a verifiable common denominator. Just as, in botany, an olive tree is recognized by a stable set of morphological and functional characteristics that repeat themselves regardless of minor variations, the process is similar in psychiatry and psychology. Diagnostic criteria operate with clear numerical thresholds: for many personality disorders described in the DSM-5, for example, a diagnosis is considered when the individual presents at least 5 of a total of 9 specific traits, approximately 55% of the established criteria, provided that such traits are persistent, inflexible, and present in multiple contexts. This proportion is not arbitrary; it derives from sensitivity and specificity analyses that demonstrate that, from this point onward, the probability of a clinically relevant condition exceeds 80% when evaluated by a trained professional.
Thus, there is a measurable, literal, and mathematical pattern. “Normal” would correspond to the absence of these pathological patterns, preserving the adaptive coherence of cognition and behavior. Neurobiologically, this coherence is linked to the functional integrity of the dorsolateral prefrontal cortex (logical reasoning), the anterior cingulate cortex (conflict resolution and attentional control), and the temporoparietal junction (social and contextual integration).
Structural or functional alterations in these areas are recurrent in neuroimaging studies of individuals with mental disorders, reflecting a greater propensity for illogical or maladaptive decisions. Consequently, it can be argued that “normal” would be one that preserves greater logical and rational consistency in the face of circumstances, not in the sense of coldness, but in the ability to interpret, consider, and act based on internal and external evidence, modulated by emotional balance.
Defining “normality” from this perspective shifts the concept from opinion to neurocognitive metrics, allowing us to reduce subjectivity and increase accuracy. After all, science isn’t about comforting beliefs, but about establishing verifiable parameters that support effective diagnoses and prevention.
Therefore, within this logic, “normal” would correspond to an individual who maintains a high capacity for logical reasoning, critical analysis, and coherence in the face of circumstances, combined with a functional emotional system. This is not an absence of emotion, but the ability to integrate it into the decision-making process without allowing it to disproportionately override reason, maintaining a balance between affective response and rational judgment, supported by harmoniously functioning prefrontal and limbic circuits.
References
KESSLER, RC et al. Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication. Archives of General Psychiatry, vol. 62, no. 6, p. 593–602, 2005. DOI: 10.1001/archpsyc.62.6.593.
WORLD HEALTH ORGANIZATION. World Mental Health Report: Transforming Mental Health for All. Geneva: WHO, 2022.
Biography:
Dr. Fabiano de Abreu Agrela Rodrigues MRSB/P0149176 holds a post-PhD in Neuroscience and is an elected member of Sigma Xi – The Scientific Research Honor Society (more than 200 Sigma Xi members have received the Nobel Prize). He is also a member of the Society for Neuroscience in the United States, the Royal Society of Biology and The Royal Society of Medicine in the United Kingdom, the European Society of Human Genetics in Vienna, Austria, and the APA – American Philosophical Association in the United States. He holds a Master’s degree in Psychology and a Bachelor’s degree in History and Biology. He is also a Technologist in Anthropology and Philosophy, with extensive national and international training in Neuroscience and Neuropsychology. Dr. Fabiano is a member of prestigious high-IQ societies, including Mensa International, Intertel, ISPE High IQ Society, Triple Nine Society, ISI-Society, and HELLIQ Society High IQ. He is the author of more than 330 scientific studies and 30 books. He is currently a visiting professor at PUCRS and Comportalmente in Brazil, UNIFRANZ in Bolivia, and Santander in Mexico. He also serves as Director of CPAH – the Heráclito Research and Analysis Center and is the creator of the GIP project, which estimates IQ through the analysis of genetic intelligence.
Dr. Fabiano is also a registered journalist, with his name included in the book of records for achieving four records, one of which is for being the greatest creator of characters in the history of the press.
Dr. Fabiano de Abreu Agrela Rodrigues MRSB holds a post-PhD in Neuroscience and is an elected member of Sigma Xi – The Scientific Research Honor Society (more than 200 members of Sigma Xi have received the Nobel Prize), as well as being a member of the Society for Neuroscience in the United States, the Royal Society of Biology and The Royal Society of Medicine in the United Kingdom, the European Society of Human Genetics in Vienna, Austria, and the APA – American Philosophical Association in the United States. He holds a Master’s degree in Psychology and a Bachelor’s degree in History and Biology. He is also a Technologist in Anthropology and Philosophy, with several national and international degrees in Neuroscience and Neuropsychology. Dr. Fabiano is a member of prestigious high IQ societies, including Mensa International, Intertel, ISPE High IQ Society, Triple Nine Society, ISI-Society, and HELLIQ Society High IQ. He is the author of more than 300 scientific studies and 30 books. He is currently a visiting professor at PUCRS in Brazil, UNIFRANZ in Bolivia and Santander in Mexico. He also serves as Director of CPAH – Centro de Pesquisa e Análises Heráclito and is the creator of the GIP project, which estimates IQ through the analysis of genetic intelligence. Dr. Fabiano is also a registered journalist, having his name included in the book of records for achieving four records, one of which is for being the greatest creator of characters in the history of the press.