The logics of Anger

Anger is part of the basic biology of the human species. It spontaneously appears in infancy, is effectively universal in its distribution across cultures and individuals, and has a species-typical neural basis.

Sell et al., 2009. Formidability and the logic of human anger. PNAS 106 (35) 15073-8 DOI: 10.1073/pnas.0904312106

I’ve always been curious about the biological basis of behaviors: the ‘layer one’ mechanisms of life. This article called my attention.

To biologically explain anger, scientists first sought to understand the purpose of anger: what was it selected for by natural selection? The answer is that it would have evolved as a bargaining tool to resolve conflicts in favor of the angry person.

We all value our own well-being as well as the well-being of others, and are willing to invest a certain amount of time and energy in these well-beings. Anger would be an ‘encouragement’ (actually more like a threat) for someone to value more the well-being of the angry person, even to the detriment of its own.

Every one gives a certain value to their own well-being and to the well-being of others. And is willing to invest a certain amount of time and resources (of energy) in these well-beings (his own and others). Anger would be an ‘encouragement’ (actually more like a threat) for the ‘other’ to place more value on the well-being of the angry person, sometimes even to the detriment of his own.

Competition and collaboration (and agression and altruism) in humans is very complex and thus hard to model. But to some extend, dependent on what is at stake and the degree of kinship of the recipient.

“Humans have cognitive systems that look for clues to kinship, and ‘recalibrate’ their altruistic actions accordingly.”

Anger is part of another cognitive system, bargaining system, that builds up on the kinship one: how can we convince someone to be altruistic towards us if we are not directly related? It depends, basically, on two things with strange names but very familiar meanings: formidability, which is the ability to ‘impose difficulties’ and conferability, which is the ability to ‘harvest benefits’. Thus, the more ‘formidable’ a person is, the more difficulties he/she is able to impose on you (right?!).

Among other things that can be taken into account by the same ‘bargaining system’ are aggression, reciprocity and externalities. All these variables are processed, together, by a ‘computational’ system of the brain that is capable of assessing the consequences of an act for yourself, for others and for each other. What you would do in a risky situation alone is not the same you would do in the same risky situation if a third loved one is involved or if it is an ‘all or nothing’ scenario.

“There is a lot of evidence that this ‘bargain evaluation system’ exists in humans as part of an intricate neural architecture and takes an active part in our decision-making processes.”

Anger is our tool to try to influence someone else’s bargain computation in a conflict situation to prioritise one’s needs.
It turns out that anger alone is probably not powerful enough to change someone else’s perspective.

In order not to risk wasting the energy of anger, the angry person makes use of two other, much more powerful, tools: the potential to inflict costs on the opponent (formidalibity), or the potential to reap benefits that are expected (conferability).

“Of course my love, you don’t have to agree with me, but then today there won’t be any slutty for you” says my sister to her husband.

Most of these transactions are more effective if they are in the realm of threat, with anger being enough to change other’s behavior to meet one’s demands, without actually having to impose aggression or deprivation. But this is only possible one’s view of their own bargaining potential (its formidability and conferability) is accurate. If it is not… either no one will pay attention to it (or refuse it anything), or dangerous conflict can be triggered.

Modern behavioral models shows that threat assessment in humans is very accurate and thus people with most bargaining power gets angry most easily. Meaning there is no ‘bluff’ in the anger ‘system’ (an exception would be the well-known ‘napoleon effect’, in which individuals try to compensate the low bargain power of their short stature by putting force into their tantrums).

Even though there is no evidence that humans know the basis for this process to work or act consciously, people who have a greater capacity to hurt or deprive others end up expecting better treatment from others and get angry easily when they don’t receive it. I bet you know someone like that, don’t you? They simply know its effects on motivation and behavior and they use and abuse it. They are the bullies!

Posted originally in 2007 in Portuguese in “Você que é biólogo…” blog