Healthcare, UK (Commonwealth Union) – Inherited traits, also known as genetic traits, are characteristics or features that are passed down from one generation to another through genes. These traits can be physical, such as eye color, height, or hair texture, or they can be behavioral, like certain personality traits or predispositions to certain diseases.
Inheritance of traits occurs through the process of reproduction, where parents pass on their genetic material, in the form of DNA, to their offspring. The genetic material is organized into units which we know as genes, which are responsible for the expression of specific traits. Genes come in pairs, with one copy inherited from each parent.
Some of the key types of inheritance patterns are dominant, recessive, and sex-linked. In dominant inheritance, a single copy of a dominant gene is enough to express the trait, even if the other copy is a recessive gene. Recessive inheritance requires both copies of the gene to be recessive for the trait to be expressed. Sex-linked inheritance occurs when a gene is located on the X or Y sex chromosomes, which can lead to different inheritance patterns in males and females.
A recent study suggests that individuals share personality traits with their parents only marginally more than they do with a random stranger. According to the study, accurately forecasting a child’s patterns of thinking, feeling, and behaving based on their parents’ characteristics is deemed impossible.
Inherited traits can have significant implications for individuals and families, particularly when it comes to health. Some genetic disorders, such as cystic fibrosis and sickle cell anemia, are caused by the inheritance of specific genes. In these cases, understanding the inheritance patterns can help families make informed decisions about family planning and medical care.
While the findings acknowledge the influence of inherited genes on traits, they underscore that genetic factors account for only half of the variation in personality among people. Additionally, the team highlights that individuals inherit only half of their genes from each parent.
“This is why the genes that a parent passes on to their children are not sufficient to make most of their personality traits similar,” said the lead author Dr René Mottus.
The research was conducted collaboratively by scholars from the University of Edinburgh’s School of Philosophy, Psychology, and Language Sciences alongside the University of Tartu in Estonia.
To gather data, the researchers enlisted over 1,000 pairs of relatives from the Estonian Biobank, a comprehensive repository of health data volunteered by individuals across Estonia.
In total, more than 2,500 individuals provided self-reports on five crucial personality traits—openness, conscientiousness, extraversion, agreeableness, and neuroticism—along with their overall life satisfaction. Notably, each participant had at least one relative participating in the study.
A distinctive aspect of this study was the inclusion of a corroborating perspective for each participant’s personality assessment. This was typically provided by an “informant,” often the participant’s partner. This dual assessment approach significantly enhanced the accuracy of trait evaluation compared to prior studies, which relied solely on self-assessment.
The findings reveal that approximately 40 percent of personality traits and life satisfaction are attributable to heredity, a notable increase from the 25 percent typically observed in standard self-report studies. However, researchers caution that this percentage alone does not imply a significantly greater likelihood for individuals to inherit personality traits from their parents compared to random individuals.
Furthermore, analyses comparing individuals with their first-degree relatives (such as parents, siblings, or offspring) versus more distant relatives found no indication that shared family experiences lead to greater similarity in personality traits. Notably, there is no evidence to support the idea that adoption into a family result in personality traits resembling those of foster parents or other children in the household.
Dr. Mottus suggests that while the findings do not definitively rule out the heritability of personality traits, they indicate that such heritability may not be statistically significant. Rather, personality traits are probably more influenced by genetic factors rather than environmental upbringing.
Dr. Mottus elaborates that according to the most precise estimates available, approximately two-thirds of the variance in people’s personality traits can be attributed to genetic factors.
“But this is not enough to make parents and children much more similar than strangers.”
The research has been published as a preprint on the PsyArXiv server and is pending peer review.
