It turns out that the absence of receptors for this hormone slows down the development of friendship but doesn’t fundamentally affect romantic relationships.
What Did the Researchers Study?
- A research team led by Annaliese Beery (UC Berkeley) and Devanand Manoli (UC San Francisco) worked with prairie voles genetically modified so that their oxytocin receptors did not function. Source: PubMed
- They conducted behavioral tests to evaluate how quickly the animals formed preferences between a familiar peer and a stranger.
- They used a “party setup”: a group of animals placed in separate rooms that could freely interact with one another. The researchers observed whether existing friendships were maintained when new strangers appeared.
- They also measured how often animals pressed a lever to reach a friend, a partner, or a stranger — an indicator of motivation to socialize with known individuals.
- For the biochemical part, they used nanosensors developed in Markita Landry’s lab (UC Berkeley) to track oxytocin release in the nucleus accumbens — a brain region associated with social reward.
Key Findings — Friendship vs. Romance
Here’s what they discovered:
- Voles without oxytocin receptors formed friendships significantly more slowly. Normal animals preferred a familiar peer over a stranger within a day, while mutants needed up to a week.
- When new strangers appeared, normal voles stayed close to their “friends,” while mutants tended to mix indiscriminately.
- In the lever-pressing task, normal females worked harder to reach a friend, whereas mutant females showed this difference only toward their partners.
- Mutant voles showed reduced oxytocin secretion and fewer release points in the nucleus accumbens.
- Romantic bonds still formed — just more slowly and less selectively.
Why Does This Matter for Humans?
Although this study was conducted on animals, its insights may be relevant to humans:
- Selective social behavior may depend on oxytocin signaling and receptor function.
- Differences in how quickly friendships develop or how motivated someone is to connect could reflect individual oxytocin system activity.
- This could deepen our understanding of conditions where social bonding is challenging — for example, autism spectrum or anxiety disorders.
- Oxytocin appears to strengthen and accelerate social connections rather than create them from scratch.
Limitations and Future Directions
It’s important to note:
- Animal studies cannot be directly generalized to humans.
- Genetic modification may influence brain development and compensatory mechanisms.
- Human social contexts are far more complex and harder to measure as precisely as in voles.
- Further research is needed to explore the oxytocin system in adults and its potential therapeutic applications.
Conclusion
Oxytocin and its receptors play a vital role in forming early friendships. They help animals more quickly recognize and maintain social closeness. The absence of these receptors doesn’t prevent romantic bonding altogether but makes it slower and less selective.
Disclaimer: This article is for informational purposes only and summarizes scientific research findings. It is not intended as medical advice. If you experience difficulties with social or emotional connections, consider consulting a qualified professional.
