Psychopathy vs. Oxytocin: Can The Love Hormone Cure a Lack Of Empathy?

Psychopathy is a personality disorder characterized by a lack of empathy, impulsivity, and antisocial behavior. These traits are divided into two groups: one linked to emotional coldness and manipulation (F1), and the other to impulsivity and aggression (F2). These characteristics affect how a person recognizes and reacts to the emotions of others. Oxytocin, a hormone related to social bonding, has shown potential to improve emotion recognition and promote empathic responses, potentially helping to treat these deficits in people with psychopathic traits.

Social coexistence depends heavily on trust between people and the ability to cooperate. These qualities are essential for maintaining healthy relationships in various contexts: in families, at work, in court, in business, and even in relations between citizens and the government.

For these prosocial attitudes to occur, the human brain has developed specific circuits that encourage ethical and empathic behavior. However, when these circuits malfunction, as occurs in people with psychopathic traits, the ability to act ethically can be compromised.

This can lead to behaviors ranging from minor offenses to serious crimes, such as large-scale fraud or even acts of mass violence, with serious consequences for society.

Psychopathy is a type of personality disorder that has been studied for a long time, dating back to the 19th century. It is characterized by a combination of specific traits, such as being superficially charming, easily manipulating others, feeling no guilt or remorse for harmful actions, having little or no empathy, being impulsive, setting unrealistic goals, engaging in criminal behavior in youth, and engaging in various types of crimes throughout life.

Although psychopathy does not officially appear as a specific diagnosis in the main manual used by mental health professionals (the DSM-5-TR), it is related to another disorder that does appear there: Antisocial Personality Disorder (ASPD). This disorder involves behaviors such as disrespecting the rights of others, lying, being impulsive, aggressive, irresponsible, and showing no remorse.

Although many traits of psychopathy also appear in Antisocial Personality Disorder, the two concepts are not exactly the same. For example, some typical features of psychopathy, such as superficial charm and a lack of empathy, are not required for a diagnosis of Antisocial Personality Disorder.

Among the most commonly used tools for identifying psychopathy are tests and scales administered by psychologists, such as the PCL-R (Hare Psychopathy Checklist: Revised), considered one of the most reliable. This instrument analyzes 20 characteristics divided into two groups:

• The first (Factor 1) assesses traits such as deceitfulness, emotional coldness, and lack of empathy;

• The second (Factor 2) analyzes impulsivity, irresponsibility, and antisocial behaviors.

These two groups reflect two main dimensions of psychopathy: one more emotional and manipulative (F1) and the other more linked to impulsivity and aggression (F2).

Studies also show that F1 traits are often linked to emotional coldness and difficulty empathizing, while F2 traits are more associated with people with a history of trauma, reactive behavior, and difficulty controlling impulses. Despite all these observations, many questions remain about how exactly the brain is involved in these traits.

Perceiving and recognizing other people's emotions is fundamental to empathy, the ability to understand and share feelings with others. To achieve this, our brains need to pay special attention to social cues, such as facial expressions or tone of voice. This attention is called "social salience." When this system malfunctions, the ability to recognize and respond appropriately to others' emotions can be impaired.

Empathy has two main components. Cognitive empathy is the ability to rationally understand what another person is feeling or thinking. Affective empathy is the ability to empathize with another person, such as feeling sad when seeing someone crying.

Psychopathy appears to have a stronger impact on affective empathy, especially in people with F1 traits (emotional coldness). People with F2 traits (impulsivity and aggression) may have difficulties with cognitive empathy.

The brain has specific areas that process these emotions, such as the amygdala (involved in fear and empathy), the ventral striatum (involved in rewards), the anterior insula, the orbitofrontal cortex, and other regions related to social perception.

Studies show that people with psychopathic traits often show different responses in these brain areas when they observe emotions in others, such as fear or sadness.

For example, the amygdala tends to be less responsive in people with F1 traits, which may explain their lack of empathy. On the other hand, people with F2 traits may overreact to emotions such as anger or frustration, which can lead to impulsive aggression.

Besides the brain, the body also responds to emotions. Pupil dilation (when the pupil enlarges when seeing something emotional) and gaze focus (where we look on a face, for example) are ways to measure emotional engagement and social attention. People with psychopathic traits often show changes in these responses, such as looking less closely at the eyes of someone who is frightened, making it difficult to identify the emotion.

Oxytocin is a substance produced by the brain and released throughout the nervous system and the body. It is known as the "love hormone" or "bonding hormone" because it is involved in behaviors such as affection, empathy, trust, loving relationships, and even childbirth and breastfeeding.

In the brain, oxytocin acts on several regions important for processing emotions, such as the amygdala, the cingulate cortex, and the hypothalamus. These areas are also involved in emotion recognition and empathy. Oxytocin also helps form social memories and regulate stress.

Many studies have tested the effects of oxytocin administered via nasal spray (called in-OT). In people without mental health problems, oxytocin improved the ability to recognize emotions in others, increased trust and cooperation, and reduced negative reactions to frightening stimuli.

It has also been observed that it increased the time people spent looking into others' eyes, facilitating the recognition of facial expressions.

Psychopathy, as we've seen, affects how people connect with others and recognize emotions. This can happen for different reasons, depending on the combination of F1 or F2 traits.

When reviewing existing studies, the researchers found no studies that directly examined the relationship between psychopathy and oxytocin simultaneously. Therefore, they analyzed studies that investigated each of these topics separately in relation to emotion recognition.

This analysis showed that the two dimensions of psychopathy (F1 and F2) relate differently to how the brain and body react to emotions, especially negative ones, such as fear or sadness. For example, in some psychopathic individuals, brain activity decreases when faced with these emotions (leading to emotional coldness); in others, it increases (generating impulsivity and aggression).

Studies on oxytocin, however, indicate that it may have a positive effect on these processes. Oxytocin appears to help increase attention to social cues, improve emotion recognition, increase pupil dilation (indicating greater emotional engagement), and reduce negative reactions in brain areas such as the amygdala. In other words, it may act as a "compensator" for some of the emotional deficits observed in psychopathy.

This study reinforces the idea that psychopathy is not a single condition, but rather a set of traits that affect emotional and social functioning in different ways. Oxytocin, in turn, may play an important role in correcting or reducing these deficits.

However, as there are still no studies that directly analyze the relationship between oxytocin and psychopathy using physiological measures (such as brain and body responses), this area still needs further exploration.

Future research may help identify more precise biological markers for each type of psychopathy and even suggest specific treatments, using, for example, oxytocin itself as an intervention tool.

READ MORE:

Psychophysiology of facial emotion recognition in psychopathy dimensions and oxytocin’s role: A scoping review. 

Sara Ferreira-Nascimento, Filipa Freire, and Diana Prata 

PLoS One, 20 (7): e0327764, July 30, 2025

https://doi.org/10.1371/journal.pone.0327764

Abstract: 

Psychopathy is characterized by social impairments that hinder effective societal functioning. It comprises two main dimensions: “Interpersonal-affective” and “Lifestyle-antisocial,” each associated with distinct patterns of traits and central and peripheral neurocorrelates, particularly concerning social salience and oxytocin function. In this review, we systematically identified and synthesized evidence from studies investigating oxytocin’s role in the psychophysiological correlates of emotion recognition across psychopathy dimensions. However, as no such direct studies were identified, we instead compiled and analyzed research examining these variables separately. A scoping review was conducted to capture studies reporting on psychopathy or oxytocin in relation to facial emotion recognition, whether or not they included central or peripheral psychophysiological measurements – retrieving 66 articles. We found distinct emotion recognition outcomes between psychopathy dimensions, some even with opposing neural activity in response to emotional expressions, particularly those of negative valence, as assessed through neuroimaging, electrophysiology, eye-gazing, and pupillometry. Oxytocin presented suggestive positive/compensatory effects on social salience, enhancing emotion recognition, and increasing pupil dilation, and eye-gazing towards faces, and decreasing brain activation towards negative emotions. This review highlights the critical need for future studies to bridge the gap between psychopathy and oxytocin research by exploring their interaction on shared psychophysiological correlates. Such efforts could facilitate the identification of dimension-specific diagnostic biomarkers and targeted interventions for psychopathy.