Oxytocin May Make Childhood Memories More Negative in People with Relationship Anxiety

Oxytocin is a hormone and chemical messenger involved in childbirth, breastfeeding, and pair bonding. Studies in mice and sheep have shown that it is essential for mothers to recognize their offspring and for adults to recognize other members of their species. Early human experiments suggested that oxytocin universally increases trust, cooperation, and empathy.

However, more recent evidence points to a nuance known as the social salience hypothesis: oxytocin acts as an emotional amplifier, making social information more prominent regardless of whether it is positive or negative.

Researchers at McGill University, led by Melissa Shemirani and Jennifer A. Bartz, recruited 77 men and women for the study. During one visit, participants received oxytocin via a nasal spray; during another, they received a placebo. Neither the participants nor the researchers knew which spray was administered on a given day.

After the hormone had taken effect, participants were shown words related to attachment, such as “protect” and “upset,” and asked to recall specific childhood experiences involving their mothers. The researchers then selected one positive and one negative memory and asked participants to describe each aloud.

Independent raters read the transcripts and assessed their emotional tone. Among participants with high attachment anxiety, oxytocin led them to describe their mothers in more negative and less positive emotional terms than they did after receiving the placebo. This suggests that the hormone amplified their underlying fears about relationships.

Participants with an avoidant attachment style, who tend to suppress their desire for closeness, became even less willing to share personal information after receiving oxytocin. The hormone reinforced their tendency to distance themselves from emotional disclosure.

The findings apply only to memories involving mothers, who have historically been treated as the primary caregivers in early psychological research. The study does not establish whether oxytocin would affect memories of fathers or other caregivers in the same way. The sample was relatively young and predominantly White and Asian, so the findings may differ in other populations.

The researchers also found a discrepancy between human raters and computer-based text analysis programs. Automated tools often struggle to capture the mixed emotions that are typical of family memories.

Oxytocin is not a universal remedy for relationship problems. Because the hormone may amplify existing social fears, its use in therapy may require individualized supervision. Without appropriate guidance, it could intensify distress in people who already experience high levels of anxiety in close relationships.