What Are We Like: Is It a Matter of Genetic Inheritance or Not? A Systematic Review

BACKGROUND. Scientific literature in psychology considers personality as an organization of ways of being, knowing, and acting that ensures unity, coherence, and continuity, stability, and planning of the individual's relations with the world. Personality is the outcome of two distinct constructs: Temperament and Character. So, personality is the result of the interaction between biological aspects (Temperament) and experiences of everyone in life, interacting with the environment[1]. Scientific literature now largely agrees that adversity in the early years of life has broad long-term consequences on the neuroendocrine, immune, and metabolic systems[2] as well as on neuroplasticity and neuronal morphology. Here we analyze the hypothesis that maternal environmental factors (air and chemical pollutants, maternal health, eating behaviors, maternal and fetal stresses, caregivers' behaviors, etc.) can cause epigenetic alterations in the offspring during the prenatal that shape the trait's personality of the offspring themselves and that partially influence their. METHODS. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was used to develop this systematic review. PubMed, Scopus, PsycINFO, and Biosis databases were searched for primary research articles published between 2010 and 2023 looking for English language articles containing the term "prenatal" and any of the following terms: "anxiety", "brain development", "depression", "gestation", "maternal health", "maternal stress", "mental health", "newborn health", "perinatal programming", "pregnancy", "prenatal stress", "resilience to stress", "transgenerational epigenetic inheritance", "personality", "personality trait", "environmental epigenetics". Relevant papers evaluating the relationship between maternal environmental factors and the personality traits of the offspring were subjected to a more thorough evaluation. RESULTS, AND CONCLUSIONS. Among the 111 studies identified, only 3 met the primary question. There is evidence to support the hypothesis of correlations between environmental exposure during the intrauterine fetal period and personality traits of the newborn. Limits: Multiple limitations were found based on the lack of research on this specific topic, although such a field of research can be important for developing effective strategies for primary prevention.