Bernd Heinrich was on a hike through the woods of New England when he observed something which would go on to change our perception of animal psychology.
A group of ravens had gathered to feed on a dead moose. But rather than choosing to keep the bounty for themselves, they were making a strange call, one which seemed to be deliberately attracting more ravens to the feast.
A biologist at the University of Vermont, Heinrich was initially confused. By helping their competitors, the ravens appeared to be defying all natural biological instinct. But as it transpired, their motivation was actually deeply selfish. The birds were juveniles who had discovered the moose in an adult raven’s territory. By inviting other ravens to join them, their intrusion was more likely to go unchallenged.
Last month, an astonishing video emerged of a rhesus macaque successfully resuscitating another of its species which had been electrocuted at a train station in India. It is tempting to describe the sustained display of persistence and apparent concern as almost human. But there is a danger in viewing animal behaviour through the misty lens of human emotion. What both Heinrich’s “sharing ravens’ and the macaques of Kampur do provide is a window into the gradual evolution of one of the most human of traits – altruism.
Altruism in its purest form should be an entirely selfless action. “If there’s any kind of selfish interest at stake, like secretly hoping for a return favour or even doing it deliberately because you know it will make you feel good, then that doesn’t really count at all,” says psychologist Michael Platt of the Center for Cognitive Neuroscience at Duke University, North Carolina.
Perhaps the only creatures on the planet capable of this, apart from ourselves, are among the simplest. Insects such as ants or honeybees are almost certainly not neurologically advanced enough to feel emotions such as empathy but are extremely altruistic, regularly sacrificing themselves for the sake of their colony. But this isn’t conscious choice, more an evolutionary drive. Ants do not reproduce as individuals, instead the colony reproduces. It renders their own survival immaterial and means they’re programmed to do whatever’s necessary to enhance the survival of the group. Their actions can be thought of as simply genetic reflexes.
There are different levels of altruistic behaviour until you reach the higher spheres of thought and emotion which only humans are capable of. Some creatures never display these traits at all, particularly the almost ubiquitously solitary reptile family.
In the majority of creatures, altruism is mostly driven by inherently selfish motives linked to survival. Vampire bats need to feed at least once every 36 hours otherwise they die but it’s common for female bats to share their spoils with roost mates who are low in nutrition and in need. Like much of animal altruism, this is actually a long-term insurance policy, a favour which is expected to be reciprocated when the time comes.
However it’s unclear whether the bats or even Heinrich’s ravens are consciously choosing to behave in this manner. It’s likely that they are born with such tendencies, replicating what their kin have always done for generations. Forms of altruism are hardwired into all creatures who live in social groups, in the same way that deep evolutionary instincts drive parents to quite extreme behaviour to ensure the survival of their offspring.
“The first animals to develop social behaviour did so because being in a group makes it easier to survive than leading a solitary existence,” Platt says. “And behaviours which helped the group such as altruism would be selected for genetically and passed down through the generations. But these apparently caring, helping behaviours are motivated by mutually beneficial interests – we’re going to do better together than alone.”
In the case of the bats, the type of altruism on offer is fairly limited. But some animals such as dolphins, elephants and in particular the primate family, are capable of forming social bonds to a far stronger extent and actually make conscious decisions to help members of their group with whom they feel a greater affinity. This is believed to be through an increased ability to feel emotion. It’s demonstrated especially strongly in some of our closest relatives. Male chimpanzees form particularly tight-knit friendships.
“Monkeys certainly have emotions and probably the ability to display empathy,” Heinrich says. “The macaque in the video is likely to have initially been acting out of curiosity and then perhaps alarm.”
But compared to even the most empathetic macaque, what makes humans unique is our willingness to go out of our way to help complete strangers, often putting ourselves in harm’s way in the process.
“There’s no known animal out there who has set up an Oxfam charity so other members of their species could donate,” Platt says. “And animals almost always display altruism to a member of the same group. But we do things for complete strangers that are quite extreme. Somebody gets pushed in front of a subway and suddenly you find yourself jumping down there and sheltering them as the train goes roaring overhead. From a purely biological standpoint, this type of behaviour doesn’t make much sense.”
Why we do this is due to a gradual chain of events, both sociological and neurological which have taken place over the past one million years. In the past two decades, studies of the neurobiology of social behaviour have identified a network of regions which have evolved to help us interact with other individuals, remember information about them, deduce what they might be likely to do, and most importantly understand their internal state and think of things which might help them. These regions form what we call the “social brain” and there are two in particular which are critical for altruism. The temporoparietal junction is involved in understanding how another might be feeling and seems to be linked to charitable giving. The anterior cingulate gyrus has been associated with empathy.
However there are other primates who share very similar brain networks and researchers are trying to to work out exactly why our own neural structure makes us so much more predisposed to this behaviour. The social parts of our brain are certainly larger than those of our closest relatives but is it merely greater size which makes us more altruistic?
Perhaps the answer also lies in the powerful social forces driving the evolution of modern humans. “At some point in our history, the identity of the group to which you belonged became as potent a force as individual biology,” Platt says.
“If you lived in a group where everyone was very helpful to each other, behaved altruistically, and your group could then dominate other groups, then those altruistic tendencies would increase in frequency and the number of groups displaying those capacities would increase.”
But even today, there is great individual and cultural variation to how altruistically minded we are, and some controversial theories have put this down to our genes.
Powerful hormones such as oxytocin are involved in bonding between friendship groups and the levels of these chemicals may contribute towards how much you can feel of another individual’s pain and how motivated you are to take an action based on that.
“Some people might be very good at understanding another person’s mental state but not necessarily act on that behaviour,” Platt says. “There are studies which suggest genes affecting oxytocin signalling might be associated with differences in altruistic behaviour. We showed that if you give it to monkeys, they’re then much more likely to offer another monkey a treat. But it’s still too premature to draw any concrete conclusions.”
