Oxytocin seems to be the key to flocking behavior in birds, as well as schooling behavior in fish. And these behaviors seem to be led by female populations. Could it be that human females are biologically wired to provide the foundation for social behavior?
But Goodson found that blocking mesotocin only affected the females; the males' behavior was unchanged. He also found that whether a species likes to congregate seems to depend on the location of the mesotocin receptors.
In the news article, Goodson doesn't speculate on why oxytocin and mesotocin are so much more potent in females. He says he hopes more work on songbirds will shed light on the question. But it's my understanding that, in humans, estrogen enhances the bonding effects of oxytocin, while testosterone mutes them. So it makes perfect sense that women -- in general -- are more interested in social connection.
Putting this together with Goodson's work on flocking, it could be that the predilection for bonding goes beyond individual connections. Perhaps women, like female zebra finches, influence society as a whole, helping us to cooperate, collaborate, trade and keep peace.
The paper, published last Friday in Science, is Mesotocin and Nonapeptide Receptors Promote Estrildid Flocking Behavior.