NEO-FIVE and genetics: what your DNA says about your personality

You probably know someone who is the life and soul of every party, and someone who would rather stay home with a book. Psychology has spent decades making sense of this human diversity with a well-known model: the Big Five personality factors, or NEO-FIVE. And we now know a good deal more about where that diversity comes from.

At ADNTRO we have just updated your genetic personality predispositions with data from the largest genetic study ever carried out on the subject, published in the prestigious journal Nature in September 2026.

What the NEO-FIVE is

The model groups personality into five broad dimensions that are fairly independent of one another:

• Openness to experience: curiosity, imagination, a taste for the new.
• Conscientiousness: organisation, discipline, goal orientation.
• Extraversion: sociability, energy, a taste for social stimulation.
• Agreeableness: empathy, trust, willingness to cooperate.
• Neuroticism: a tendency towards negative emotions and stress.

We all have all five dimensions, just to differing degrees, and that unique combination is what draws your personality profile.

Is personality inherited? Robert Plomin’s legacy

Robert Plomin, professor at King’s College London and one of the most influential figures in behavioural genetics, helped answer this question by comparing identical twins (100% of DNA shared) with fraternal twins (50%). If a trait has a genetic component, identical twins should resemble each other more closely in that trait, and that is exactly what was observed in personality, time and again.

That is where a much-quoted figure comes from: between 40% and 60% of personality differences between people are associated with genetic differences. This does not mean that “half of your personality is in your DNA”. It means that a good part of the variability between people is related to genetics. Your genetics sets predispositions, not destinies; upbringing, experience and our own decisions act afterwards. If you are interested in the detail of those twin studies, we cover it in how genetics influences behaviour.

The largest genetic study of personality to date

In September 2026, the international ReGPC consortium published in Nature the most powerful genetic analysis of personality carried out so far, with data from up to 1.18 million people. It found 1,260 regions of the genome associated with the Big Five, 65% of them new. Neuroticism, for example, went from 224 to 706 known regions.

The key finding is not how many regions there are, but what they confirm: no single gene determines a personality trait. Each variant contributes a minuscule effect, and it is the sum of thousands of them that builds a measurable predisposition.

The study also measured how much of the differences in personality is explained by the genetic variants we are able to detect today with a genotyping analysis. This is what is known as SNP heritability. That figure ranges between 11% and 16% depending on the trait, well below the 40–60% of twin studies. This does not mean that genetics matters less than was thought, but that we do not yet know the full detail of its influence: rare variants and gene–environment interactions are left out.

That is why genetic predispositions let us know the tendency of our personality “from birth”, but at no point do they indicate the percentage we have of each trait. For example, a high result (90% in agreeableness) indicates a genetic predisposition in the 90th percentile. Not that the person has that trait at 90%.

Genetics sets tendencies, not inevitable outcomes: even the best-established effects act on large population groups, never on one particular person. Your environment and your own decisions still have the last word. Read your updated ADNTRO report for what it is: a snapshot of your biological starting point, not a closed label on who you are.

Conscientiousness

Measures the capacity for self-regulation, achievement orientation, organisation and impulse control when pursuing long-term goals.

A high genetic predisposition is associated with organised, steady and dependable people, good at planning and able to postpone immediate gratification in favour of future goals.

A low genetic predisposition, on the other hand, is associated with more spontaneous and flexible people, who may procrastinate, be easily distracted or improvise rather than follow a strict plan.

Technical summary

• SNP heritability: 11.2%.
• Featured gene — CADM2: synthesises a synaptic adhesion molecule that is especially active in reward and self-control circuits. It is one of the most replicated genes in human impulsivity: it is associated with sensation seeking, risk taking and substance use.
• Links with other behaviours: the study linked greater genetic conscientiousness with more physical exercise, less alcohol and tobacco consumption, and lower body weight.

Neuroticism

Measures the tendency to experience negative emotions — anxiety, sadness, irritability — and emotional reactivity to stress.

A high genetic predisposition is associated with more emotionally reactive people, more prone to worry, to perceive their surroundings as threatening and to experience mood swings.

A low genetic predisposition, on the other hand, is associated with calmer, more self-assured people who are resilient under stress (emotional stability) and rarely feel overwhelmed.

Technical summary

• SNP heritability: 12%.
• Featured gene — CRHR1: encodes a receptor involved in the hormonal regulation of the stress response. In mice, switching it off directly reduces anxiety-like behaviour; in humans, its variants modulate how stress and the risk of anxiety/depression interact. A very solid link with neuroticism.
• Links with other behaviours: it is by far the trait most tied to mental health, associated above all with anxiety and depression.

Extraversion

Measures the tendency to seek social stimulation, energy in interaction with other people and comfort with being the centre of attention.

A high genetic predisposition is associated with sociable, talkative and assertive people, who recharge in the company of others and enjoy social stimulation.

A low genetic predisposition, on the other hand, is associated with more reserved and reflective people (introversion), who prefer small groups or solitude to recover energy after social interaction.

Technical summary

• SNP heritability: 15.8%, the highest of the five dimensions.
• Featured gene — KANSL1: regulates the activity of other genes during brain development; when it works below normal levels, the people affected are very consistently described as especially sociable and good-natured.
• Links with other behaviours: the study linked greater genetic extraversion with having had COVID-19 more often, very possibly because of greater exposure due to more social interaction.

Agreeableness

Measures the tendency towards cooperation, trust, empathy and maintaining harmonious relationships with others.

A high genetic predisposition is associated with empathetic, cooperative and trusting people, willing to help and prioritising harmony in their relationships.

A low genetic predisposition, on the other hand, is associated with more competitive, sceptical or direct people, who put their own interests first and give ground less easily in a disagreement.

Technical summary

• SNP heritability: 10.8%, the lowest of the five dimensions.
• Featured gene — FOXP2: known as the “language gene”, key to the development of speech and communication, the basis of empathy. It acts as a general regulator of the neurobiological development of speech.
• Links with other behaviours: it is the trait with the most consistent relationship with a lower likelihood of mental health problems, although also the one with the most variable genetic signal across countries and cultures, so its results are worth interpreting with a little more caution.

Openness to experience

Measures intellectual curiosity, imagination, aesthetic sensitivity and the willingness to explore ideas, openness to change and ways of life different from one’s own.

A high genetic predisposition is associated with curious and imaginative people, with a taste for art and abstract ideas, who enjoy exploring new places, cultures and ways of thinking.

A low genetic predisposition, on the other hand, is associated with more practical and conventional people, comfortable with routine and certainty, who prefer the tried and tested over taking on change.

Technical summary

• SNP heritability: 15.2%. This does not mean that the PRS explains 15.2% of our openness to experience, but that it explains 15.2% of the variability observed in the population.
• Featured gene — NEGR1: involved in how neurons connect during brain development.
• Links with other behaviours: the recent study linked openness to experience with a greater tendency to take part in scientific studies.