A newly published article in Nature has shed some light on how we make decisions, and also the closeness of the relationship between humankind and our nearest evolutionary relatives. A team of psychologists led by Oxford Professor Matthew Rushworth, including Dr. Alessandro Bongioanni and Dr Miriam Klein-Flügge, have shown that the area of the brain activated when monkeys make decisions using novel information matches that in humans. 

Previous studies seemed to suggest that humans and monkeys used different areas of their brain for decision making, but the work of the Rushworth group demonstrated that this difference was not due to technological error, but a difference in the type of decisions being studied – novel decisions activate different neural regions to familiar decisions. Deciding to watch Bridget Jones’ Diary for the 3rd Valentine’s Day in a row, for example, activates the area of the brain associated with revisiting familiar information; a different system is activated when you have to choose between starting Bridgeton at the behest of your friends or starting a new murder mystery series.

The latter, involving novel rather than learned behaviour, requires the ability to speculate, hypothesise, and synthesise information, an ability typically assigned only to humans. According to Dr. Bongioanni in a blog post written about the paper, the conclusion of this study “bridges a gap between our knowledge of the human and the animal brains”: if rationality has been seen as a definitely human capacity, the demonstration of monkeys’ ability to undergo novel decision making in a way similar to humans raises some fascinating questions.

The capacity for making novel decisions is present in both humans and primates, so how important is it to our day to day lives? We’ve all been spending a lot more time at home recently, and it often feels as though our daily routines are leading to stagnation, rather than to novelty. 

Speaking to Cherwell, Dr. Bongioanni speculated that although this increase in the proportion of familiar to novel experiences is advantageous from a decision-making perspective, in that familiar environments allow our brain to expend less effort, it may have less ameliorative effects in other areas of neurological health: “[T]his may not be great for us as human beings,”, says Dr. Bongioanni, “because novelty is usually enriching and stimulating, and falling into routines is likely to cause a loss of motivation and even potential emotional disorders.” 

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Although the neural circuitry for novel decision-making is similar in humans and primates, Dr. Bongioanni also pointed out that “boredom is a very specific human emotion”. Whilst it may be that the brains of the monkeys that took part in the experiment demonstrated the ability to respond to novel scenarios, animals “don’t get bored, they don’t mind repeating the same routines again and again”. 

Discussing the boredom that can arise when our routines begin to stagnate, Dr. Bongioanni noted that the proclivity of younger people to get bored more easily than older people is “evolutionary adaptive, because young people have more to learn”: the boredom we feel reading another comedian making another joke about banana bread or Tiger King is not only inherently human, but also a sign of our brain’s ability to constantly adapt to novelty.The area of the brain involved with novel decision making, according to Dr. Bongioanni, is far from isolated. Part of a wider neural circuit known as the Default Mode Network, this region of our brains activates “when we fantasise, or we think about ourselves or make future plans.” Perhaps we can combat the isolation and monotony of our current situation with exercise of the imagination, but Dr. Bongioanni stresses the cutting-edge nature of these ideas: “to understand precisely how this works will require a lot more research.” In the meantime, there’s always To All The Boys: Forever and Always to be cracking on with.