Evolutionary biology concerns the study of traits such as: genetics, morphology, physiology, and different types of behaviour that are present today in the natural world. Study in this field is done with the objective to make sense of these phenomena through understanding how, or why they may have developed (Harvey and Pagel, 1991). Two behaviours, that are observed in the natural world, and will be the focus of this paper are: Altruism and Spite. Altruism is defined in the Oxford English Dictionary as ‘selfless concern for the well-being of others’, whilst spite is simply defined as ‘A desire to hurt, annoy, or offend someone’. (Simpson, 2008). These straightforward, brief definitions do well to explain these behaviours in the literary world however, the characterisation of both of these behaviours within the field of evolutionary biology is often disputed. This paper seeks not only to outline the different definitions of these behaviours present in the field but also to ascertain, through the use of real-life examples and behavioural studies, whether these behaviours exist in the animal kingdom. In addition to this, this essay aims to settle upon two definitions that describe each behaviour in a zoological context, as they are truly present in nature. Finally, both altruism and spite are behaviours that can be seen throughout the human world, which consists of a society based upon frequent co-operation and antagonism between unrelated individuals, on a huge scale. Using examples from both events in human society, and evidence from behavioural studies of animals, this paper aims to consider whether these behaviours are distinctly and uniquely human or simply, an inevitable part of life for all in the animal kingdom.
Main body:
Altruism and Spite are two of four, basic social behaviours that can be observed across the animal kingdom, and are classified based upon their cost or benefit to the acting animal, and those around them (Gardner and West, 2006). These four behaviours include: altruism, mutualism, selfishness and spite. Social behaviours evolve, and are explained evolutionary, through a cost benefit analysis, which determines how each behaviour effects the ‘fitness’ of an individual. ‘Fitness’ refers to how each behaviour affects the ability of an animal to survive and reproduce, and it is widely agreed that a behaviour will evolve if it increases the fitness of the ‘actor’ that carries it out (Fisher, 1930). Both mutualism and selfishness are easily explained through the lens of evolution, as both behaviours lead to direct benefits for the actor (Hamilton, 1964). Conversely, Altruism and Spite are more puzzling to explain.
In a Zoological context, Altruism is most simply defined as the ‘behaviour of an animal that benefits another at its own expense’ (Simpson, 2008), whilst Spite is classified as behaviour where both the actor and recipient suffer a loss of fitness (Gardner and West, 2006). Notoriously, Hamilton’s rule is able to explain these behaviours through ‘Kin Selection’. Hamilton’s rule states that altruistic behaviour will occur if the cost to the actor is outweighed by the benefit to the recipient, multiplied by the relatedness of the recipient to the actor (Hamilton, 1964). Therefore, relatedness is a key factor in determining whether an altruistic act is carried out, meaning that animals are much more likely to help their kin. This rule can also be re-worked in order to explain the occurrence of Spite if the cost to the actor is smaller than the result of the negative action, multiplied by the negative relatedness of recipient to the actor (Gardner and West, 2006). To explain this further, negative relatedness refers to when two or more individuals are less related than the mean relatedness in a population (Wang, 2014). This, therefore, connotes that individuals are more likely to act spitefully towards those that are less related to them, or non-kin. These rules help to explain how these behaviours have evolved.
Now that basic definitions and explanations for altruism and spite have been established, the question remains as to whether Spite or Altruism are able to exist as interactions between non-kin in nature, and if so, how have these behaviours evolved? To begin to address these questions, it is pertinent to look at examples of these behaviours in nature, and the conditions that are needed to facilitate them. One such example of altruism that occurs in nature is ‘Reciprocal Altruism’. Reciprocal altruism is a co-operative behaviour in which one individual aids another, with the prospect of the recipient returning the behaviour at a later time (Trivers et al, 1971). This form of altruism, thus argues that rather than a direct benefit, it may be the prospect of a future benefit to the actor that allows altruistic acts to be carried out. This portrays reciprocal altruism as a useful argument when explaining how altruism is able to evolve and be observed between unrelated, or distantly related animals. An example of this reciprocal altruism is mobbing behaviour as seen in Pied flycatchers, who work together with kin and non-kin alike, to drive away potential predators from specific nests. These birds are seen to refuse to participate in mobbing behaviour when it is initiated by others who had failed to co-operate earlier (Krams et al, 2007). This means that in the long term, though mobbing predators for another bird’s nest costs energy and reaps no direct benefit to the actor, such as the preservation of related genes. It is still a useful behaviour to evolve, as in future other flycatchers may return the favour.
• There is evidence of altruism across the human world, from acts of bravery to philanthropy (NEWS EXAMPLES). Selfless acts of kindness are of a behaviour that is not only prevalent, but, venerated, and encouraged across human society. Human examples of altruism: A Mechanism for the Evolution of Altruism among Non-kin (food shared/ food gathered together).
• Altruism Mathematically makes sense (Caporeal et al). Nature is more complex i.e. Prisoners dilemma
• Highest human co-operation: able to communicate or Know each other vs Strangers, high also with punishment for non-co-operation- like pied flycatchers (Bohnet and Frey, 1999)
• Compare to similar experiments with Chimps (Jensen et al, 2006)
• Theorise importance of communication for altruism [see notes]
• Move onto Spite via correlation of spite and wealth
Equally, another behaviour that is apparent across the human world is spite. From robbery to vandalism and ultimately murder there are, unfortunately, many human examples of spite. Of course, across the natural world, there are plenty of examples of ‘unkind’ behaviour or Spite when animals are looked at through the lens of anthropomorphism. These behaviours range from carnivory and parasitism to selfishness, and violence during territorial or mate competition. In actual fact, though harsh from a human perspective, all of these behaviours have an important role regarding the survival of all animals. A lion must fight to protect its kill just as an elephant seal must defend its right to mate with a group of females or a pork tapeworm must utilise its host for its own survival. What makes spite distinct from these behaviours, is that it involves the expenditure of energy, a valuable currency for all animals, to the detriment of the intended target, but also to seemingly no direct benefit to the animal that commits the act.
• This spiteful behaviour is seen, perhaps most clearly, through the ’Mafia hypothesis’ in Cuckoos (Soler et al, 1995) and also green beard queen killing in fire ants (Foster et al, 2001).
• More examples of altruism that are both disputed and accepted such as: ‘Co-operative breeding’ or ‘Helping’ in and wolf packs, and callitrichids including marmosets and golden tamarins, (Harrington 1983, Skutch 1961, Burkardt, 2009, Fry 1972; Brown 1974; Ricklefs 1975).
• Other examples include food sharing in Vampire bats (Wilkinson, 1990), 3R’s needed for altruism (Recognition, repeated interactions, reciprocity)
• Human altruism is distinct as not always repayable e.g: rescue someone from drowning (news example?) however, this could be less different to animals as first thought. Perhaps the distinction is that indirect reciprocity requires a higher-level storage and transmission of information to keep track of reputation? Humans can hope to be repaid in the future, more so than animals do, if so then altruism can be selected for (Nowak and Sigmund, 2005). Unless they die doing a good deed (examples of good deeds concerning certain death)- is this unique to humans?
• Another possible explanation: Uniquely human concepts such as morality, guilt and religion. Humans are perhaps able to reward themselves- rid themselves of guilt, see a higher purpose- dopamine pathways triggered by good deeds ()/ biologically speaking they are able to save energy by clearing their conscience – this could be a direct benefit? Luyten, P., Corveleyn, J. and Fontaine, J.R., 1998. The relationship between religiosity and mental health: Distinguishing between shame and guilt. Mental Health, Religion & Culture, 1(2), pp.165-184.
• Constructs within human society mean that those that do good/altruistic acts e.g charity/military war heroes are glorified i.e. Remembrance Day spectacle, even after 100yrs/ good publicity for charity. Thus altruism increases attractiveness to ‘mates’? Thus, confers a direct benefit? Recent evidence for this in humans: Everett, Jim A. C.,Pizarro, David A.,Crockett, M. J. Journal of Experimental Psychology: General, Vol 145(6), Jun 2016, 772-787
• Similar arguments explain spite in humans. Though energy expenditure may not result in a direct physical benefit, humans may be able to satisfy the need for a reward mentally e.g. non-peaceful protests/vandalism.
• In addition to this passion/strong action may indicate attractiveness i.e. the ‘altruistic trait’ may serve as a handicap (Zahavi, 1975), whereby only mates with sufficient fitness can afford to act this way, this then generates a reliable signal of the genetic quality of the altruistic individual (Miller, 2001). If the cost of altruism is compensated by higher success during sexual selection, then it will be selected for, hence altruism evolved.
• Spite may evolve through punishment, though no direct benefit, there is less cost to actor than receiver, I.e. punishment, may serve to encourage co-operation Hilbe, C. and Traulsen, A., 2012. Emergence of responsible sanctions without second order free riders, antisocial punishment or spite. Scientific reports, 2, p.458.
• Although our species may be born to be innately helpful (Tomasello, 2009), or innately selfish with the ability to learn to care for others (Hobbes, 1651), we are prepared to be altruistic and even harm others in specific contexts (Zizzo and Oswald, 2001). Social behaviour is complex with the collective interest competing with instinct.