(Il)logical Reasons for Making Difficult Decisions
You’re in a burning building. With you is your closest friend, and the doctor with the cure for (let’s say) cancer in his memory, and only in his memory. Both are trapped under rubble, and luckily you are able to help. However, the fire is spreading fast and clearing rubble takes time, so you think you will only be able to save one person. I want you to genuinely consider who you would choose to save in this situation and why.
This may seem like a difficult choice, but choosing between multiple right answers is something we’re all used to, though the stakes are usually not as high as a burning building. Why did you choose to read this blog? How do you choose one thing on a menu, when it all looks so good? Reasoning and decision making under risk and uncertainty are as natural as breathing, and to that effect we don’t really give it much thought. For this moment however, I invite you to consider it a little more, as you continue reading.
Contemporaries like Rips (1994) believed we reason like rule-based logical machines, which has some truth to it. Logic is an important part of reasoning. Without being exhaustive, we can make inferences deductively, inductively and abductively (Khemlani, 2018).
Deductive reasoning decreases semantic information, drawing specific inferences from general information. Using the scenario at the start, if I read on the news, after the incident, that a cure for cancer had been developed, I could deduce that you opted to save the doctor. Inductive and abductive reasoning differ as they add semantic information. Inductive reasoning making general conclusions from specific principles, and abductive reasoning making the simplest explanations from observations. For example, inductive reasoning might lead me to conclude that because you saved the doctor, a cure for cancer will be in development, whereas abductive reasoning might lead me to conclude that you saved the doctor because you believed their cure would go on to save even more lives.
Rational choice theory posits that rational agents make decisions that bring us the most benefit with the least cost (Scott, 2000). If we look at the costs and benefits in terms of lives saved, then in our scenario the cost of saving the doctor (your own friend’s life) is far outweighed by its benefits (the doctor’s own life, plus the countless others his cure saves). This leads us to believe that the rational thing to do would be to save the doctor without a second thought, but in practise, it is not so simple.
In the real world, there are many costs and benefits that would need to be taken into account and weighed up against each other. For example, if that oxytocin hit a friend gives you (Brent, Chang, Gariépy & Platt, 2014) is a bigger subjective benefit than the lives that doctor could save, then an equally rational being could choose to save their friend instead. However, unsurprisingly, not all our decisions are rational, which is especially evident when we reminisce on emotion-fuelled actions in our past. Prospect theory is an encompassing theory stating we make decisions based on a multitude of heuristics, including loss aversion (Kahneman, 1979). This states that we are much more sensitive to potential losses compared to potential gains, which might be why we have to ponder whether sacrificing one close friend who is in our lives is worth saving countless other people who are not.
We also make inferences based on default reasoning, which incorporates semantic information of how we see the world, causing us to make somewhat illogical assumptions based on incomplete information (Khemlani, Leslie, & Glucksberg, 2012). For example, whilst there was no logical reason to assume the doctor in our scenario was male, it was an inference likely made by people who believe that male-ness is a generic characteristic of doctors in general.
In conclusion, we may not be logical machines more than we may be machines that use logic. Many situations require us to use logic to have the best reasoning or make the best decisions, but there are at least as many situations in which we use heuristics to help us. Next time you find yourself reasoning about a difficult and/or risky decision you have to make, consider whether you’re making it logically or heuristically. If you find yourself looking for new insight, let me suggest the following: note what your heuristic guided gut feeling guides you to do, then think about the most logical/rational alternative, and perhaps consider the middle ground between the two.
References
Brent, L. J., Chang, S. W., Gariépy, J. F., & Platt, M. L. (2014). The neuroethology of friendship. Annals of the New York Academy of Sciences, 1316, 1.
Kahneman, D. (1979). Prospect theory: An analysis of decisions under risk. Econometrica, 47, 278.
Khemlani, S., Leslie, S. J., & Glucksberg, S. (2012). Inferences about members of kinds: The generics hypothesis. Language and Cognitive Processes, 27, 887–900.
Khemlani, S. S. (2018). Reasoning. Stevens’ Handbook of Experimental Psychology and Cognitive Neuroscience, 3, 1–45.
Rips, L. J. (1994). The psychology of proof: Deductive reasoning in human thinking. Mit Press.
Scott, J. (2000). Rational choice theory. Understanding contemporary society: Theories of the present, 129, 671–85.
