Uncovering the complex genetics of human character

Area of Science:

• Behavioral genetics
• Neuroscience
• Genomics

Background:

• Human personality exhibits significant heritability (30-60%).
• Identifying specific genetic variants influencing personality has been challenging.
• Self-regulatory personality traits (character) are crucial for health.

Purpose of the Study:

• To uncover complex genetic networks and environmental interactions influencing personality using machine learning.
• To identify genetic variants associated with character traits measured by the Temperament and Character Inventory (TCI).

Main Methods:

• Genome-wide association studies (GWAS) employing machine learning.
• Analysis of a discovery sample of 2149 healthy Finns, with replication in Korean and German samples.
• Identification of single-nucleotide polymorphism (SNP) sets and their association with personality profiles.

Main Results:

• Five distinct personality (character) profiles were identified.
• 42 SNP sets linked to 727 gene loci were significantly associated with character profiles.
• These SNP sets explained 50-58% of personality heritability and were replicable across diverse populations.
• Environmental factors showed small but significant effects.

Conclusions:

• Self-regulatory personality traits are substantially influenced by complex interactions among over 700 genes.
• These genetic sets modulate specific brain molecular processes related to goal-setting, self-reflection, empathy, and memory.
• Genetic architecture of personality is robust across cultures and environments.