Kind, aggressive, horny or erratic. It's all on your hormones. But if you think that being smart is just an issue regarding neurons, you're wrong: it is also about hormones. Recent researches show the hormone oxytocin boosts at least one cognitive skill: penetrating inside the mind of the others.

Because humans are social beings, it is crucial for them to understand the motives, intentions, goals, desires, beliefs and feelings that drive the others, for achieving harmonious social interaction. We must see what makes others different, and others what makes us different, forecasting the behavior of the individual inside a social group, a skill named "theory of mind," (ToM) that ensured the evolutionary success of the human species.

A new research led by Gregor Domes at the University of Germany shows how oxytocin is involved in reading the others' mind.
Oxytocin is a peptide (small molecule protein) synthesized in the brain (by the magnocellular neurosecretory cells within the supraoptic nucleus and paraventricular nucleus of the hypothalamus). Released in the blood, it will target the mammary glands, provoking lactation during breast feeding, but also uterine contractions during labor and delivery. But in the brain and the spinal cord, it works like a neuromodulator, tuning neuronal activity.

Studies made on rodents and primates revealed oxytocin and vasopressin, a similar peptide and are crucial in attachment and affiliative types of behavior like pairing, maternal behavior, sexual behavior, separation distress and social memory (the skill to recognize a former partner over time). Mice lacking oxytocin could not recognize a previously encountered mouse. Oxytocin shots before meeting a new mouse made these individuals acquire this social ability.

Synthetic oxytocin administered nasally to humans increased trust (in the context of making investment decisions) and controlled brain responds to fearful factors.

Domes' team offered nasally a synthetic type of oxytocin (Syntocinon) or placebo to 30 healthy men (aged 21-30).
After that, the subjects completed a test determining how they could determine other peoples' mental states. They watched images of actors within an array of emotional expressions like shame, alarm and bewilderment. The images revealed only the eye region, important for the detection of more complex emotions.

The subjects had to choose from four descriptive words the best one that revealed the actor's state. Oxytocin improved significantly this skill.

The finding could be important for shedding light on conditions of impaired social functioning, like autism, when individuals find it difficult to read the emotions of others, through facial expression, voice or posture, making impossible social functions like reciprocity and empathy.

Previous researches pointed that oxytocin and vasopressin (more precisely, their shortage or lack) could be amongst the factors causing autism. Autistic adults offered synthetic oxytocin (Pitocin) decreased repetitive behaviors (a main symptom of autism) during a 4-hour period.

Oxytocin appears to ease the processing of social information received through two sensory pathways: hearing and vision. This hormone also was found to regulate stress and fear reactivity, explaining the theory of mind by decreasing the social anxiety accompanying many social encounters, an acute symptom in autism.

This peptide could also create motivation to attend to social cues by increasing social information processing. Prairie voles have more oxytocin and vasopressin receptors in brain areas linked to reinforcement and motivation, like nucleus accumbens, compared to the more solitary mountain voles.