Change is one of the few constants in human life. Technology evolves, social norms shift and scientific discoveries regularly overturn what was once considered fact. Yet humans can struggle to adapt even when change is unavoidable, beneficial or clearly understood.

The difficulty is not necessarily a refusal to accept change. At a psychological level, change disrupts the systems people use to make sense of the world.

Part of the answer lies in how the brain predicts what will happen next.

Rather than simply reacting to information, the brain is constantly making predictions about its surroundings. This idea, known as predictive processing, suggests that the brain builds an internal model of the world and compares its predictions with what actually happens.

When the two do not match, the brain produces what neuroscientists call a prediction error. This is not a mistake in the usual sense. It is information that tells the brain its model needs updating.

In 1978, Finnish neuroscientist Risto Näätänen and colleagues published research using EEG to investigate how the brain responds to unexpected sounds. Participants heard a repeated series of tones, with occasional changes in pitch.

Even when they were not paying attention to the sounds, their brains produced a distinct electrical response when a tone changed. This became known as mismatch negativity, suggesting that the brain had formed an expectation about what it would hear and detected when reality did not match it.

In other words, the brain can notice that something has changed before we consciously realise that it has changed.

Change in everyday life can work in a similar way, although on a much larger scale. A new workplace, technology or social environment can invalidate predictions that have previously worked reliably. That creates uncertainty.

Researchers have investigated this using brain imaging. In a 2018 meta-analysis, scientists combined results from 87 neuroimaging studies looking at uncertainty in situations involving threats, rewards and decision-making.

They found that uncertainty repeatedly involved areas including the anterior insula, a region involved in detecting significant changes in internal and external states, and the amygdala, which helps process emotional information.

This does not mean the amygdala simply tells us that change is frightening. Instead, these systems help the brain work out whether something important has happened and whether a response is required.

However, there is another problem: dealing with uncertainty requires cognitive control.

The prefrontal cortex, at the front of the brain, is involved in functions including attention, decision-making and cognitive flexibility: the ability to adjust our thinking when circumstances change.

Research by neuroscientist Amy Arnsten has shown what happens when stress interferes with this system. In laboratory and animal studies, researchers found that high levels of stress-related chemicals can weaken the neural connections supporting prefrontal cortex activity, while strengthening more primitive, rapid-response circuits.

This could explain why major changes can feel mentally exhausting. The brain may need greater flexibility when stress makes flexible thinking harder.

But the brain is not permanently stuck with its original predictions.

It can adapt through neuroplasticity, which is the ability of the nervous system to change its connections and activity in response to experience. Every time someone encounters a new environment and discovers that it is predictable and manageable, the brain gains more information with which to update its model.

Eventually, what was unfamiliar can become familiar.

This may be the crucial distinction. Humans are not necessarily bad at change. We are good at adapting to change, but adaptation requires the brain to gather enough information to make the unfamiliar predictable.

The discomfort comes from the period in between.

When the old model no longer accurately describes the world, but the new one has not yet been built, uncertainty increases and more conscious effort is required.

So the difficulty of change may not come from an inherent dislike of the new, it may come from something much more fundamental. The brain works most efficiently when it can predict what happens next. Change temporarily takes that certainty away.

Image credit: Unsplash