I was fortunate enough to share an online session with the very psychologist who coined the term — ‘behavioural immune system’; Mark Schaller, a professor of Psychology at the University of British Columbia. Basically, the term refers to a suite of psychological mechanisms that allow individual organisms to detect the potential presence of disease-causing parasites in their immediate environments and to engage in behaviours that prevent contact with those objects and individuals. This behavioural immune system is clearly apparent in some of the human kind’s most irrational and extreme measures as well. However, the intent is to prevent infection and ensure survival.
In many ways, our behavioural immune system works exactly like our body immune system. In the case of the later, it activates itself when a foreign body threatens our health by finding an entry into our system. And to fight it off, our immune system summons some extreme measures. A common example is a fever. It isn’t without costs. As a matter of fact, the brain has to use up more than 30% of its usual share of energy in order to increase our body temperature by one degree Celsius (which is why we feel fatigued). So, it is fair to say that it isn’t quite a desirable position to be at. In Mark’s own words, our body immune system is more like medical insurance; It feels good to have one but it feels shi**y to use it. This is where the behavioural immune system gains its relevance. Rather than trying to wage a war against the infections, this system tries to prevent it in the first place.
An example that most would be familiar with, is the way pregnant women react to certain cuisines and situations. Do remember that at this stage, they are immunosuppressant, which means they can’t possibly fight off many infections at this stage. Many dishes that were their favourite, might even disgust them during the gestation period, preventing them from taking a bite. This may not necessarily mean that the thing they are disgusted by is a threat to their life or their offspring, it just means that it might be. We just are not willing to take a chance. This is kind of a rational case of the behavioural immune response. However, the most common sightings of this mechanism involve irrational responses from our part.
An example that Mark itself provides is an easy way to understand the phenomenon. One of his office staffs bought a box of cookies. The peculiarity of the chocolate cookie was its unusual shape, it looked like dog sh*t. He offered them to his colleagues. Even though his friends were perfectly aware that the cookies were chocolate and that the shape had no significance, they were unwilling to respond to the offer positively. Even the our cognition makes it clear that it is safe, something prevents us from taking a chance. That something is what we call- behavioural immune response.
Another common example are prejudices that we hold for ourselves. This could be displayed as racism, out-group bias or even discrimination. Again, there needn’t be any rationality behind our behaviour other than acting out of our desire for survival. Imagine that you from India and you hear about the coronavirus break-out in Wuhan, China. You would probably, at least for some time, try and maintain a safe distance with any Chinese that you encounter. Even if you are sure that there is no possibility for the man to have been infected and that any other person close to you have an equal chance to be a carrier, you would still choose to avoid the Chinese. Such stereotypes and prejudices can be rooted in our instinctual desire to survive. But that doesn’t mean that it is logical or rational by any standard. What we should do is ask ourselves before our immune system kicks in, is it worth it? Most often it is not.
When the lockdown associated with the pandemic eases, you might experience the effect of our behavioural immune system. We might not be tempted to hug a stranger, we will think twice before pressing the switches of a public elevator, we might feel uncomfortable sharing a cab with a fellow being…
