Hannah Critchlow: The 21st Century Brain
The Cambridge neuroscientist who says the future of wellbeing lies in how adaptable our brains really are-
Neuroscientist Hannah Critchlow has spent years exploring what she calls “the 21st century brain” — how modern life, technology and AI are reshaping the way we think, feel and connect.
A Fellow at Magdalene College at the University of Cambridge, Hannah believes the future of wellbeing lies not in resisting change, but in understanding just how adaptable the human brain really is.
Here, she reflects on emotional intelligence, brain fog, uncertainty and why human connection matters more than ever.
Is technology outrunning our human evolution?
“No — because embedded within our brains is this extraordinary mechanism known as synaptic plasticity.
If we look back through human history, periods of rapid technological change are nothing new. In the 21st century BC, humanity was already undergoing enormous shifts. The written word was becoming widespread, metal tools and weapons were transforming society, and people were beginning to live in increasingly complex city states.
Fast forward to the 21st century AD, and we’re experiencing another profound transformation. We’ve developed technologies that allow us to communicate across the globe instantly. The internet, social media, and now artificial intelligence have fundamentally changed the way we interact and process information.
What’s particularly fascinating is that many AI systems have been inspired by our growing understanding of the brain itself — especially the way neural networks operate to create human intelligence.
But the reason I’m optimistic is because the human brain is remarkably adaptable. Synaptic plasticity allows us to learn from our environment, form new memories, develop new behaviours and continuously evolve.
It’s this flexibility that enables us to innovate, solve problems and ultimately thrive — not just in the 21st century, but far beyond it.”
Why do so many of us experience brain fog nowadays?
“I think many of us feel as though it’s becoming harder to think with clarity and precision, and there’s no doubt that modern life places huge demands on our attention and cognitive energy.
We’re constantly processing information, switching between tasks and navigating environments that can feel mentally overwhelming. But there are still some very powerful ways we can support the brain and help it function more clearly.
Nutrition is a key part of that. Our brains require a huge amount of energy and a steady supply of nutrients to function well, so eating a healthy, balanced diet really matters. Highly processed foods often lack the nutritional value our brains and bodies need.
Sleep is equally important. During sleep, the brain consolidates what we’ve learned throughout the day into more stable memories. It’s also when many of the restorative processes that support focus, learning and emotional regulation take place.
And then there’s exercise. Regular movement has a profound impact on the brain. We know that physical activity can stimulate the growth of new nerve cells, particularly in the hippocampus — a region deeply involved in learning, memory and navigation.
So while brain fog can feel like a symptom of modern life, there are still very practical ways we can strengthen and support the brain’s ability to focus.”
Is emotional intelligence a skill we can develop?
“Yes — absolutely. One of the really exciting things emerging from neuroscience and psychology is a growing appreciation for the role emotions play in helping us navigate the world.
For a long time, emotions were often seen as something irrational or disruptive. But we now understand that emotions carry important information and can actually guide decision-making in very useful ways.
What’s particularly interesting is that emotional intelligence doesn’t appear to be strongly heritable. In other words, the genes we inherit from our parents don’t seem to determine this ability more than our environment or cultural background.
Instead, our environment and experiences play a much larger role — and that’s encouraging, because it means emotional intelligence is something we can actively develop throughout our lives.
There are simple ways to nurture it. Making direct eye contact, for example, helps strengthen human connection and empathy. Practising self-compassion is also incredibly important — taking the time to notice and listen to our own emotional responses rather than suppressing them.
And interestingly, reading fiction can help too. Fiction places us inside other people’s worlds. It allows us to experience different perspectives, emotions and journeys, which in turn helps us build empathy and social understanding.”
Why do humans struggle so much with uncertainty?
“Our brains, as sophisticated as they are, essentially function as prediction machines.
Every second, our senses are taking in an enormous amount of information — millions of bits of data continuously flowing in from the world around us. Yet consciously, we’re only aware of a tiny fraction of that information.
The brain filters and simplifies reality so we can function efficiently. It’s constantly using past experiences to predict what’s likely to happen next.
The challenge is that uncertainty disrupts those predictions. When we enter unfamiliar situations or face ambiguity, the brain has to work much harder because it can no longer rely on familiar patterns. That can feel mentally and emotionally uncomfortable.
So one of the most important things we can do is support the nervous system during periods of uncertainty.
A small amount of stress can actually be beneficial — it can enhance brain plasticity and help us adapt. But chronic stress, fear and prolonged anxiety can become harmful over time and negatively affect brain health.
That’s why mindset matters. If we approach uncertainty purely through fear, the brain tends to become more defensive and rigid.
But if we can approach it with curiosity, openness and a sense of possibility, we create the conditions for adaptability and growth.
Uncertainty is uncomfortable, but it’s also where innovation, creativity and transformation often begin.”
Published: 02 June 2026
Images: Getty images (J Studios); Joseph Byford; Getty Images (Jacob Wackerhausen); Getty Images (Janina Steinmetz).
Video: Adam Page
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