Networks of molecules in our body behave as though they have goals and desires. Understanding this phenomenon could solve the origins of life and mind in one fell swoop
Tom Gauld
We all struggle with self-control sometimes. We tell ourselves only one more piece of chocolate, one more glass of wine, one more episode of a binge-worthy series before bed, but then carry on regardless. But who, or what, even is this “self” engaging in this push and pull, before giving in to temptation? The cells in our gut somehow collaborate with those in our brain and hands to reach for the chocolate bar, the wine bottle or the “next episode” button. And, with ever-increasing complexity, at some point a line is crossed, and the whole becomes more than the sum of its parts. That is to say, a self – the entity which acts in the world in ways that serve your goals and desires – emerges.
What if, though, “selves” are present in those very cells, ahead of the point at which they merge to form a greater whole? It might sound outlandish, but biological simulations are indicating that those minuscule units of life, which we usually think about as passive machines – cogs blindly governed by the laws of physics – have their own goals and display agency. Surprisingly, even simple networks of biomolecules appear to display some degree of a self, a revelation that could lead to novel ways of treating health conditions with far fewer side effects.
What’s more, some biologists say this new grasp of selfhood can reveal what is special about life and how it began in the first place. “The origins of agency coincide with the origins of life,” says cognitive scientist Tom Froese at the Okinawa Institute of Science and Technology in Japan.
Intelligent agents
Selves are more technically defined by biologists and neuroscientists as “agents” that have goals and act in ways that achieve those goals. Agents aren’t simply pushed around by their environment, but alter themselves and their environment in purposeful ways. In other words, they have causal power over themselves and their environment.
To behave with agency, you need to absorb information, use that information to solve problems and then learn by remembering how those actions turned out. Neuroscientists broadly call this “cognition” and use brain scanners and behavioural experiments to study this constellation of processes. Indeed, we traditionally ascribe cognition only to things with brains. “It’s easy to get caught up in the idea that brains are our first example of cognition, and a lot of people therefore think that brains must be special [in this respect],” says theoretical biologist Emily Dolson at Michigan State University.
But a growing number of researchers have been investigating where else these abilities show up, applying similar methods to much simpler organisms that lack brains in any conventional sense. In the past few years, studies of the behaviour and electrical and chemical signalling of slime moulds, plants and even single-celled organisms have revealed surprising abilities such as learning, forming memories and adjusting decisions as new information arrives. They have even extended the scope of cognition to smaller systems within the human body: the immune system, for instance, constructs its own memory of which proteins will help it ward off harmful invaders, and groups of cells collaborate to grow and repair the body of their own volition. In other words, both the immune system and these cell collectives are acting with degrees of agency in their own right.
Slime moulds challenge our understanding of intelligence and what it means to have agency Sinclair Stammers/naturepl.com
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