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The Love Drug: Oxytocin and its implications to social interaction

meroberts's picture

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            Oxytocin has been considered a “love drug” and it has even been marketed as a “trust serum” in an inhalant form as a result of recent evidence elucidating its role in romantic attachments and sexual behavior. It is well-kown that oxytocin is responsible for uterine contraction during childbirth, lactation, and is released during sexual orgasm in both women and men (UCSF, 1999). Oxytocin has also been found to be a key hormone in the bonding process between mother and infant. In fact, oxytocin is influential in creating bonds between anyone, not just a mother and her child. This paper serves to explain how oxytocin functions physiologically, facilitates social interaction, and possible pharmacological interventions using oxytocin to help people with Autism Spectrum Disorders better recognize emotional cues will be introduced.

             The oxytocin molecule is described as a peptide chain, comprised of nine amino acids (Bowen, 2007). This hormone is synthesized in the hypothalamus and secreted into the blood stream primarily by way of pituitary gland axons. A few other tissues, including the sexual reproductive organs of both sexes, also secrete oxytocin into the blood. The evidence regarding the physiological role of oxytocin implies that it is influential in the process of childbirth and child-rearing. In the case of both lactation and uterine contraction during childbirth, the primary role of oxytocin is to stimulate smooth muscle (myoepithelium) contraction. The smooth muscle contraction in the mammary glands results in the expulsion of milk from the alveoli, or the milk sacs in the gland. When the milk exits the alveoli, it can be stored in ducts to facilitate the process of breast-feeding. In the case of uterine contraction, the myoepithelial cells are stimulated when the fetus applies pressure to the cervix and vagina as it prepares to exit the birth canal. This stimulation results in a stronger contraction of the uterine myoepithelium, which ultimately facilitates birth. In addition to the auxiliary role of oxytocin in preparing for childbirth, the hormone is also influential in shaping maternal bonds and establishing maternal behavior (Bowen, 2007).

            Although oxytocin plays an instrumental role in childbirth, it is actually secreted by both men and women, indicating that oxytocin accomplishes another function; oxytocin actually facilitates social interaction and bonding. In both men and women, oxytocin is secreted during sexual orgasm, and because of this it is believed that oxytocin “may be involved in adult bonding” (UCSF, 1999). Oxytocin has long been a hormone associated with increased sexual receptiveness and a desire to engage in cuddling behaviors. The fact that it is secreted not only by mothers during the late-gestational period and during childbirth, but also by both men and women during sexual orgasm points to its role in creating and maintaining intense emotional bonds.

            From an evolutionary perspective, these intense emotional bonds form the basis for the nuclear family unit. It explains why there is a tendency (even if it is influenced by social constraints and norms) amongst humans to form stable partnerships from which the partners draw strength in their ability to properly care for their young. Oxytocin also acts as a reinforcing agent to ensure that mothers have a vested interest (in the form of an intense emotional bond) in caring for their young, as human neophytes are incapable of caring for themselves until several years after birth. This is also an excellent example of the brain’s ability to interpret, and respond to, signals before the I-function even recognizes the resultant behavior as its own.

            For example, Dr. Diane Witt of Binghamton University says “that since the release of oxytocin can be classically conditioned, after repeatedly having sex with the same partner, just seeing that partner could release more oxytocin, making you want to be with that person all the more” (Is Oxytocin, n.d.). In this case, the I-function would be asserting to the individual that they are in love with their partner, whereas the brain is actually just producing this perception in response to its interpretation of the heightened levels of oxytocin present in the blood stream as a result of the association between the partner and previous sexual stimulation. This subconscious recognition of an intense emotional bond, and the initial ability to form this emotional bond, all point to oxytocin as a major facilitator of social interactions and intense emotions associated with bonding.

            The previous research has focused on oxytocin as it relates to childbirth and sexual attraction, but very little research has emphasized oxytocins role in mediating other forms of social interaction; that is, until now. Very exciting research has just indicated that oxytocin could be used as a new miracle drug to improve social behavior of, and emotional recognition in, children with Autism Spectrum Disorders. In a study conducted by Angela Sirigu at the Centre de Neuroscience Cognitive (CNRS) it was found that “the inhalation of oxytocin, a hormone known to promote mother-infant bonds and social relationships, significantly improved the abilities of autistic patients to interact with other individuals” (CNRS, 2010). The hormone was applied as an inhalant to 13 people with autism and their resulting behaviors were observed during ball games and visual tests designed to measure their ability to recognize emotions through facial expressions.

            The 13 individuals were diagnosed with either Asperger syndrome (AS) or high-functioning autism (HFA). The study was restricted to these diagnoses to ensure that cognitive ability was intact in the participants. The impetus for this study arose from previous findings that implied that “levels of this hormone in the blood of patients showed that it was deficient in those with autism” (CNRS, 2010). The team ultimately concluded that oxytocin allowed the participants with high-functioning forms of autism to increase their attention to social signals when examining several photographs of faces. It was even noted that these subjects spent more time looking at the eyes of the people in the photographs. This is particularly intriguing because these Autism Spectrum Disorders (ASD) are characterized by an inability to maintain eye contact. Usually, people with an ASD find it hard to look directly at someone resulting in avoidance of eye contact and a general lack of social interactions.

            During the ball game, three partners were given specific instructions. One was told to throw the ball only to the subject with ASD, another was told to throw to any of the four individuals playing, and a third was told to never return the ball to the participant with ASD. Each time the subject with ASD received the ball, he or she was awarded a sum of money. The purpose of the game, then, was to determine whether or not the participants with ASD could discern who would help them win the most money by cooperating and interacting with the other individuals in the ball game. When given a placebo, the participants with ASD were not able to determine who would be most cooperative in their mission to win the most money. After the inhalation of oxytocin, though, the participants “were able to discriminate between the different profiles and returned the ball to the most cooperative partner” (CNRS, 2010). It is clear that there is a need for further study of oxytocin as a possible treatment for ASDs in the future, but the evidence to date supports the notion that oxytocin reduces social dysfunction in individuals with ASD.

            Similarly, in a study conducted by Australian autism researchers, adolescents with ASDs “were asked to complete a facial expression task that measures emotion recognition” (Elsevier, 2010). The participants completed this task on two occasions, each one week apart. On one occasion, the participants were given a placebo inhalant and in the other they were administered oxytocin as an inhalant. It was determined that participants’ performance on the task improved when given the oxytocin as compared to the placebo. The subjects were better able to recognize emotion through the facial expressions (Elsevier, 2010). This is an exciting breakthrough for the treatment of ASD, and the field of psychology in general because throughout its history as a disorder, autism has been characterized by “a difficulty in understanding and reciprocating the emotion of others” (Elsevier, 2010). With the implementation of oxytocin as a treatment for people with an ASD, barriers to social interaction are broken down by the reduction of fear associated with social interactions and the increased feelings of intimacy, or closeness, associated with social interactions as a direct result of oxytocins effects.

             Oxytocin has a long history of facilitating social interactions and creating deep emotional bonds, especially between a mother and her child. The physiological underpinnings of oxytocin are fairly well-understood in the process of childbirth and in caring for children, as well as in sex. While these functions have been known for a very long time, little research has been done to determine other beneficial effects of oxytocin. It should come as no surprise, then, given its description as a “truth serum” or a “love drug”, that oxytocin may be influential in forming deep emotional bonds amongst friends and in facilitating social interaction by creating feelings of closeness and reducing fear associated with these interactions. The lower levels of endogenous oxytocin in people with an ASD is further evidence that oxytocin could very well be a promising line of treatment. This research marks the advent of an exciting new time in the therapy of ASDs. The only question that remains is, why hasn’t anyone thought of this earlier?


Bowen, R. (2007, April 28). Oxytocin. Retrieved from

CNRS (Delegation Paris Michel-Ange) (2010, February 17). Autism: Oxytocin improves social

            behavior of patients, study finds. ScienceDaily. Retrieved April 11, 2010, from

Elsevier (2010, April 10). New treatment for social problems in autism? Oxytocin improves emotion recognition. ScienceDaily. Retrieved April 11,  2010, from

University Of California, San Francisco (1999, July 15). Hormone Involved In Reproduction May Have Role In The Maintenance Of Relationships. ScienceDaily. Retrieved April 10, 2010, from­ /releases/1999/07/990715062344.htm

Is Oxytocin the body’s own love potion? (n.d.). Retrieved from




Paul Grobstein's picture

oxytocin and sociability

"oxytocin may be influential in forming deep emotional bonds amongst friends and in facilitating social interaction by creating feelings of closeness and reducing fear associated with these interactions."
This is an interesting extension of thinking about oxytocin. I wonder if Williams syndrome kids have high oxytocin levels? See Genes, brains, and being social.  And I wonder if we want to presume that "difficulty in understanding and reciprocating the emotion of others" is necessarily always a "disorder' that needs correction.  See Institute for the study of the neurologically typical

Paul Grobstein's picture

Oxytocin and Williams syndrome