A new psychological study suggests that certain forms of harsh parenting in childhood are tied to the emergence of troubling personality traits in adulthood – traits linked to manipulation, emotional coldness and even enjoyment of others’ suffering.
When strict parenting crosses a line
Many parents believe in being “firm but fair”. Yet the new research, carried out in Spain and published in the journal Personality and Individual Differences, suggests that once discipline turns severe or frightening, the impact can go far beyond a few bad memories.
Psychological and severe physical aggression in childhood were closely associated with higher levels of dark personality traits later in life.
Researchers surveyed 370 adults aged 18 to 80 about how they were disciplined as children and asked detailed questions about their current personality. Most participants were women and many had a university education, but the patterns that emerged were strikingly consistent.
What psychologists call the “dark tetrad”
The study focused on what psychologists call the “dark tetrad” – four personality traits that tend to cause serious problems in relationships, workplaces and society at large.
- Narcissism: an inflated sense of self-importance and a constant need for admiration.
- Machiavellianism: a cold, strategic willingness to manipulate others for personal gain.
- Psychopathy: low empathy, impulsivity and a tendency toward antisocial behaviour.
- Sadism: taking pleasure in the pain, humiliation or suffering of other people.
Most people show tiny traces of one or more of these traits. That does not make them dangerous or abusive. Problems arise when these traits are strong and consistent across situations, which can damage friendships, romantic relationships and professional life.
How childhood experiences can set the stage
Previous research has long linked rough childhoods to higher risks of crime, addiction and mental health difficulties. This new work looks more precisely at how parenting styles may nudge personality development in darker directions.
The basic idea is simple: children adapt to the environment they grow up in. In homes where rules are unpredictable, affection is conditional and discipline is frightening, certain survival strategies can start to look useful.
- In a volatile household, learning to manipulate or control others (machiavellianism) can feel like protection.
- When a child is repeatedly hurt or humiliated, shutting down empathy and acting on impulse (psychopathy) can become a shield.
Traits that help a child cope in a hostile family may later look like cruelty, coldness or manipulation in adult life.
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How researchers measured harsh parenting
Four types of parental discipline
To understand what kind of discipline matters most, the team used a standard questionnaire asking adults to recall how their parents usually reacted when they misbehaved. The tactics were grouped into four categories:
- Non-violent discipline: such as calmly explaining why a behaviour was wrong.
- Psychological aggression: shouting, screaming, verbal humiliation or threats.
- Minor physical aggression: for example, a slap or spanking with a hand.
- Severe physical aggression: actions like choking, violent shaking or beating.
Participants reported how often these things happened, from “never” to “more than 20 times”. While memories are never perfect, patterns across hundreds of people can still reveal strong trends.
Measuring dark personality traits
The same volunteers then completed personality scales that tap into the dark tetrad. They rated how strongly they agreed with statements such as:
- “Most people can be manipulated.” (machiavellianism)
- “People say I am out of control.” (psychopathy)
- “I think about hurting people who annoy me.” (sadism)
Higher scores indicated stronger tendencies toward these traits, even if the person was not a clinical case or an offender.
What the study actually found
When the team analysed the data, they saw that all forms of harsh discipline showed some positive link with dark traits. But once they accounted for everything at the same time, two types of parenting stood out.
| Type of parental discipline | Linked dark traits in adulthood |
|---|---|
| Psychological aggression (shouting, insults) | Psychopathy and sadism |
| Severe physical aggression (choking, beating) | Machiavellianism, narcissism and psychopathy |
| Minor physical aggression (spanking) | No unique link once severe violence was considered |
| Non-violent discipline | No unique link to dark traits |
Shouting, humiliating and seriously hurting children showed the clearest association with adult traits like manipulation, callousness and enjoyment of cruelty.
By contrast, non-violent discipline and mild physical punishment did not predict dark traits when the more extreme forms of aggression were taken into account. That does not make milder punishment harmless, but it suggests that the psychological and severe physical forms are particularly risky.
Why harsh words can cut deeper than expected
The strong link between psychological aggression and later psychopathy and sadism is striking. Constant screaming, threats or mocking may tell a child that emotions are dangerous and cannot be shared safely. Over time, some children may stop caring about others’ feelings because their own feelings were never treated as valid.
Repeated humiliation can also turn anger outward. A young person who has been routinely belittled may feel a powerful urge to gain power over others, or to enjoy moments when someone else is made to suffer. That dynamic feeds directly into sadistic tendencies.
Genetics, context and the limits of the study
This research does not claim that parenting alone creates dark traits. Personality is shaped by genetics, temperament, peers, culture and random life events. Some children show difficult traits early on, which can also make parenting more stressful and conflictual.
The study has other limits:
- Participants had to recall their childhood, which can be coloured by time and emotion.
- The sample was mostly educated women in Spain, which may not reflect other populations.
- The design was cross-sectional, meaning cause and effect cannot be firmly established.
Still, the consistent links between severe discipline and dark traits fit with a wider body of evidence on childhood adversity and adult behaviour.
What this means for parents and professionals
For parents, the findings suggest that the tone and intensity of discipline matter as much as the rules themselves. Setting limits is part of caring, but frequent shouting, threats or physical intimidation can shape a child’s character in unwanted ways.
Calm explanations, clear boundaries and repair after conflict seem far less likely to feed dark tendencies than fear-based control.
For teachers, doctors and social workers, the research adds weight to calls for early support in families where psychological or physical aggression is common. Addressing these patterns early may reduce not only short-term harm but also longer-term risks for antisocial or exploitative behaviour.
Key terms that help make sense of the findings
Psychological aggression
This refers to behaviours like yelling, name-calling, ridicule, threats of abandonment or constant criticism. There may be no bruises, but the child’s sense of safety and worth is shaken. Over years, that emotional climate can be as damaging as some forms of physical violence.
Resilience and protective factors
Not every child exposed to harsh discipline develops dark traits. Some are buffered by:
- Supportive relationships with other adults, such as grandparents or coaches.
- Access to therapy or school-based counselling.
- Personal coping skills and problem-solving abilities.
- Stable, safe environments outside the home, like clubs or community groups.
These protective factors can partly offset early damage and steer personality development in a healthier direction.
What future research could reveal
Researchers now want to follow children over many years, tracking how early discipline, genetic tendencies and later experiences interact. Such long-term studies could show which children are most vulnerable, and which interventions are most effective at redirecting risky developmental paths.
There is also growing interest in understanding how therapy, parenting programmes and social support can soften entrenched dark traits in adults. While personality is relatively stable, there is evidence that people can learn to manage impulses, build empathy and change harmful relationship patterns when given the right tools and motivation.