Altruism in Religionless Rats

No one who has ever kept rats as pets (as I have) will be surprised by a study that appeared in yesterday’s Science and is getting major media coverage. In “Empathy and Pro-Social Behavior in Rats,” the authors report:

Whereas human pro-social behavior is often driven by empathic concern for another, it is unclear whether nonprimate mammals experience a similar motivational state. To test for empathically motivated pro-social behavior in rodents, we placed a free rat in an arena with a cagemate trapped in a restrainer. After several sessions, the free rat learned to intentionally and quickly open the restrainer and free the cagemate. Rats did not open empty or object-containing restrainers. They freed cagemates even when social contact was prevented. When liberating a cagemate was pitted against chocolate contained within a second restrainer, rats opened both restrainers and typically shared the chocolate. Thus, rats behave pro-socially in response to a conspecific’s distress, providing strong evidence for biological roots of empathically motivated helping behavior.

It may seem gratuitous to point out that rats don’t have religion and I do so only because evolutionary theists often argue that religion evolved because it makes people cooperative and altruistic. Religion, in their view, is an evolutionary adaptation targeted by natural selection because it creates or enhances empathy and pro-sociality.

Those who make this argument usually ignore the fact that empathy, cooperation, and altruism are widespread in nature. Non-human primates are intensely social and quite cooperative, as are elephants and dolphins. Now we can add rats to the list. Religion isn’t necessary to explain these behaviors.

When confronted with these facts, evolutionary theists usually resort to one of two arguments. The first is that religion makes people more empathetic and pro-social than they would otherwise be without religion. While this may true of post-Neolithic religions which first linked supernatural beliefs to “moral” behaviors, this relatively recent development says nothing about the evolutionary origins of religion.

The second argument is that religion would have made human groups more cohesive and given them a competitive advantage over other groups. While it may be true that post-Neolithic religions functioned as ideological glue for larger groups (group size being the most important predictor of group level success), there is no evidence that human group sizes increased until after the domestication of plants-animals approximately 12,000 years ago. Again, this relatively recent development says nothing about the evolutionary origins of religion.

Speaking of group size, if you are considering rats as pets — something I recommend — remember they are social and you will need to get at least 2 and preferably 3 or  more, all of the same sex (unless you want lots of babies, which I don’t recommend). For reasons that weren’t clear to me until yesterday, I’ve always had females. The study found that females are slightly more empathetic and pro-social than males.


Bartal, I., Decety, J., & Mason, P. (2011). Empathy and Pro-Social Behavior in Rats Science, 334 (6061), 1427-1430 DOI: 10.1126/science.1210789

This post was chosen as an Editor's Selection for

Did you like this? Share it:

5 thoughts on “Altruism in Religionless Rats

  1. J. A. Le Fevre

    A slightly more nuanced view of the data paints a different picture. A feature of the archaic human population is that all members are dead by 35 years of age. A distinguishing feature of the humans who had religion (aka ‘modern humans’) is that some individuals lived into their sixth and seventh decades. To me, a doubling of the lifespan suggests a significant improvement in the altruism and nurturing shared among these ‘modern’, religious humans. I have argued (on your site) that this altruism and nurturing improvement is plenty enough to explain all other advances observed among modern humans.

    A man is not a mouse (some may be rats – but don’t socialize as well).

  2. Cris Post author

    We largely agree or I think we do. I think it depends on what you mean by “modern” and what time frame you are referencing.

    Also, we really don’t know when humans began having longer life spans, though I have written a paper on it which I’d be happy to send you. Can I get your email again?

    If I recall correctly, I think I argued (based on the sparse data) that a long human life span may be yet another modern or recent development, i.e., post-Neolithic.

  3. Pingback: News » Blog Archive » Editor’s Selections: Snakes, Dangerous Honey, and Friendly Rats

Leave a Reply