Is oxytocin really the love and trust chemical? Or is it just the hype hormone? A new paper suggests that many studies of the relationship between oxytocin and behaviors such as trust have been flawed.
The paper is a meta-analysis just published by Norwegian researchers Mathias Valstad and colleagues. Valstad et al. found that the level of oxytocin in human blood, often used as a proxy measure of brain oxytocin, has no relation to central nervous system oxytocin levels under normal conditions.
Valstad et al. combined the results of 7 studies that compared plasma oxytocin against central oxytocin in humans. Central oxytocin was in most cases measured in the cerebrospinal fluid (CSF) via spinal tap . The headline result was that there is no evidence of a correlation between plasma and central oxytocin at baseline in humans (r = 0.05, p = .59).
By contrast, following treatments which increased oxytocin ...