Oxytocin is as sexy a neuropeptide as they come.
"Baby Oxytocin" by Cordelia Cembrowicz
Known primarily for its role in female reproduction and lactation, recent studies relating oxytocin to differences in human behavior frequently lead to its description as a "trust hormone" or "love hormone". In fact, oxytocin has such a positive image, that - quite disturbingly- you can even purchase body sprays containing oxytocin from Amazon as "
liquid trust" (which the producers webpage markets with the ridiculous slogan "The first oxytocin product, formulated to enhance people's trust in you").
Although oxytocin is indeed crucially involved in many processes of human bond formation and trusting, the hormone-behavior-relation is not as simple as the cute monikers and silly marketing ploys suggest. Instead, in the light of actual research, a more nuanced view of oxytocin appears more realistic; one in which oxytocin is appreciated for its central role in how the brain encodes social memories and links these memories to subsequent social stimuli. Still very sexy, but not quite liquid trust.
To think of oxytocin in this more nuanced fashion seems prudent not only in light of potential, unknown biochemical interactions that take place in the human brain, but is suggested even by some of the things we do already know from research.
For example, oxytocin isn't the warm-and-fuzzy feel-good chemical that makes people gullible and indiscriminately trusting. Although you may splash on as much "Liquid Trust" as you want (or can afford at $40 an ounce), how people react to your new body odor depends to a great extent on other available cues, and will be highly context specific; actually, it may even back-fire on you as some research suggests:
Consider the following study, which let participants play an economic trust game after being administered oxytocin.
In the experiment, participants had to make risky investment decisions for which the returns depended crucially on the trustworthiness of a fellow investment partner. While oxytocin did enhance participants trusting behavior when they were matched with an investment partner who was described as trustworthy (or when playing with a computer who was described as choosing randomly), participants behavior was unaffected by oxytocin when the investment partner was presented as untrustworthy. Not only, does the study indicate that oxytocin does not magically make people more trusting irrespective of other cues, but the additional finding that oxytocin did have an effect on behavior when participants were matched with a computer program, implies that oxytocin may act on general risk perception, independent from human-to-human interaction.
Another study which highlights the "prickly side of oxytocin", undertook to investigate whether behavioral effects of oxytocin differed for interactions between people deemed as belonging to one's "in-group" vs those who are considered as "out-group". Here the research finds that administration of oxytocin did indeed increase cooperation among in-group members, but under certain settings also triggered non-cooperation towards out-group members; although primarily motivated by a desire to protect one's in-group. As the press release puts it: Participants administered oxytocin, display
"more "defensive aggression" toward outsiders, preemptively punishing members of a competing group when their own group [is] in danger of suffering a heavy financial loss".
And according to the studies lead-scientist, Carsten De Dreau
"The important message here is that oxytocin is not just promoting generosity and benevolence and trust. It's a double-edged sword.".
This double-sidedness of oxytocin can be seen in yet another study which appeared last week in the Proceedings of National Academy of Science: In this study, the researchers set out to investigate the "effects of oxytocin on peoples recollections of maternal care and closeness". In particular, they hypothesized that oxytocin's role in attachment bond formation does not imply a strictly positive effect on participant's recollections of maternal care, but that instead,
"Rather than positively biasing maternal recollections for everyone, oxytocin should bias these recollections in a positive or negative direction, depending on the nature of one's attachment style".
Their data shows that on the one hand, less anxiously attached people indeed show a beneficial response to oxytocin in that they remember their relationship with their mother in childhood more positively while influenced by oxytocin. But on the other hand
"oxytocin exacerbated chronic concerns about closeness and the reliability of close others that characterize attachment anxiety."
; making people with attachment anxiety remember their relationship to their mother in childhood less fondly than would be the case without increased availability of oxytocin in their systems.
As this most recent study points out in its closing remarks, the results found so far
"contrast with the popular notion that oxytocin has broad positive effects on social perception and are more consistent with the animal literature, which emphasizes oxytocin's role in encoding social memories and linking those memories to the reward value of the social stimulus."
Indeed, most of the scientific literature on oxytocin and its effects on human behavior includes remarks of the kind that contrast the research view of oxytocin to its popular image as a sexy trust hormone. With people out there trying to sell trust by the bottle, it is something I like to keep in mind.
The incredibly smart oxytocin-inspired art at the top of article is from this website. Check out some of the artists other cool ideas.
Main References:
Miller, G. (2010-06-11) The Prickly Side of Oxytocin. Science, 328(5984), 1343-1343. DOI: 10.1126/science.328.5984.1343-
Bartz JA, Zaki J, Ochsner KN, Bolger N, Kolevzon A, Ludwig N, & Lydon JE. (2010) Effects of oxytocin on recollections of maternal care and closeness. Proceedings of the National Academy of Sciences of the United States of America. PMID: 21115834
De Dreu, C. K. W. (2010-06-11) The Neuropeptide Oxytocin Regulates Parochial Altruism in Intergroup Conflict Among Humans. Science, 1167(1), 124-1411. DOI: 10.1126/science.1189047
Mikolajczak M, Gross JJ, Lane A, Corneille O, de Timary P, & Luminet O. (2010) Oxytocin makes people trusting, not gullible. Psychological science : a journal of the American Psychological Society / APS, 21(8), 1072-4. PMID: 20631321
