Desmodus Rotundus Vampire Bat
Desmodus Rotundus Vampire BatMerln D Tuttle

IN 1983, a biologist studying vampire bats in the forests of Costa Rica made a remarkable discovery: Bats that spent the night gorging on blood returned to their caves and routinely fed fellow bats that didn’t find enough to eat. The story of how well-off bats care for their hungry brethren by regurgitating into their mouths made vampire bats the darling of scientists who ponder why - in a world shaped by “survival of the fittest’’ - so many creatures help each other, even at a cost to themselves.

Lately, I have been wondering what these bats mean for American politics, at a time when the very idea of helping needy fellow Americans has come under assault. Newt Gingrich routinely attacks President Obama as a “food stamp president.’’ Rush Limbaugh calls the safety net for the poor “one of the biggest cultural problems we have got.’’ A Tea Party Express audience yells “yeah!’’ when Wolf Blitzer asks if an uninsured man in a hospital should just be left to die. As I watch all this, I can’t help but wonder: Are we are really less generous than bats that suck blood?


So I call up Gerald Wilkinson, the biologist who discovered bat altruism.

I ask: “Are vampire bats all bleeding-heart liberals? Are they socialists?’’

Wilkinson’s answer: “Not exactly. If they were not helping each other, they would not live very long.’’

Vampire bats, he explains, can only survive a couple of days without drinking blood. And it turns out that even the most hard-working bat has a relatively high chance of coming home empty-handed. So they feed each other because they know that one day they will need someone to return the favor.

So I ask: “Could a lazy bat live its life on the dole, lounging around the cave while other bats work overtime?’’


Wilkinson: “In a big group, it is conceivable that a bat could live on the dole. But I doubt it happens.’’

He tells me that even though bats give a fair bit to their needy neighbors, it is still far less than a bat would eat if it were successful on its own. Furthermore, bats seem to have developed mechanisms for limiting such cheating: They prefer to share with bats who have shared with them in the past. And they only give to bats they know. A strange bat that comes begging would probably starve.

It dawned on me that people are not so different. Many are willing to help a neighbor they know will return the favor, but are far more reluctant to give to a stranger who they are not sure will ever pay them back.

During times of economic trouble, when even the most hard-working can come home with nothing, people enthusiastically pay into a system that they can rely on for help if they are empty-handed. Look at how the Great Depression sparked the advent of Social Security.

But in times of plenty, well-off people start to wonder whether the poor are really just temporarily down on their luck, or if they are perpetual freeloaders who threaten to bring down the entire system. Look at how the economic boom of the 1990s gave rise to comprehensive welfare reform aimed at ensuring that no one could just collect a check for life.


In reality, human beings have been helping each other survive since the beginning of time, just like vampire bats. But we have always developed cultural norms to ensure that our altruism isn’t exploited, just as the bats have.

Perhaps one of the problems of our society today is that some have amassed so much wealth that they can’t imagine ever needing help, and they start to wonder what’s the point of helping others. And perhaps another less-apparent problem is the way we help each other today. Instead of feeding needy neighbors we know, we pay into a distant, anonymous system that leaves us wondering whom we are helping and if they will ever return the favor.

It leaves us wondering if they are people like us who are just down on their luck, or if they are cheaters who are just waiting around to suck our blood for free.

Farah Stockman can be reached at fstockman@globe.com. Follow her on Twitter @fstockman.