Your brain is not for thinking – it’s for survival and balance

When most of us think about the brain, we tend to associate it with thinking—solving problems, making decisions, or engaging in intellectual discussions. However, according to Dr Lisa Feldman Barrett in her chapter ‘Your Brain Is Not for Thinking’ from Seven and a Half Lessons About the Brain, thinking is not the brain’s most fundamental function.

In fact, the brain’s primary function, from an evolutionary and developmental perspective, is to ensure our survival by managing the body’s resources—a process she refers to as maintaining the body budget.

In this article, I focus on this key concept from the first part of Dr Barrett’s book. For a deeper understanding of how the brain works, I highly recommend reading the full book, where Dr Barrett explores additional fascinating insights into the brain’s role in our functioning.

What is allostasis (body budget)?

The concept of the ‘body budget’ represents how the brain constantly works to manage the resources that our body needs to function. Imagine your brain as the accountant of your body, ensuring that essential functions like heart rate, energy levels, digestion and oxygen supply are balanced in real time. Much like a financial budget where you monitor deposits and expenditures, the brain tracks energy reserves and adjusts our body’s functions to maintain equilibrium.

Scientifically, this process is called ‘allostasis’. Allostasis is a physiological mechanism of regulation in which the brain anticipates and adjusts the body’s energy use in response to environmental demands. Rather than merely reacting to changes, allostasis involves the brain predicting needs and making proactive adjustments to ensure stability. This constant balancing act allows the body to maintain optimal functioning in a changing environment.

For instance, when you are physically tired after a long day of work, it is not just because your muscles are worn out—your brain has monitored and calculated your energy expenditure throughout the day, signalling that it is time to rest and restore your body budget.

The role of prediction in body budgeting

Dr Barrett emphasises that the brain’s primary role is not reactive but predictive. Rather than merely responding to what is happening in the environment, the brain is constantly forecasting what resources your body will need based on past experiences and current conditions. This predictive function allows the brain to make micro-adjustments before the need arises, ensuring that you remain balanced, healthy and alert.

For example, when you reach for your morning coffee, your brain is not just reacting to your craving for caffeine—it is predicting that the caffeine will help increase your energy and regulate your body budget for the day ahead.

Similarly, in moments of stress, the brain prepares the body by releasing stress hormones like cortisol, anticipating the need for extra energy to handle the challenging situation.

How emotions tie into the body budget

What does this have to do with emotions? Dr Barrett argues that emotions are not abstract feelings disconnected from the physical world but are deeply tied to the brain’s management of your body budget. Emotions like fear, anxiety or happiness are signals that the brain sends to prepare or adjust your body’s resources.

Consider fear: when your brain perceives a potential threat, it triggers the fight-or-flight response, releasing adrenaline to ensure that your body has enough energy to either confront or escape danger. In this case, fear is not just a mental state—it is an emotion deeply connected to your brain’s prediction that you will need extra resources to protect yourself.

Practical implications: why the body budget matters for health and wellbeing

Understanding the concept of the body budget has important implications for everyday life, particularly in managing stress, emotional regulation and mental health. When we ignore the body’s signals—like pushing through fatigue or suppressing emotions—we disrupt the body budget.

For instance, if you continue to push through fatigue without resting, it’s like overspending from a financial budget without replenishing your resources. Over time, this can lead to an ‘energy bankruptcy’, making it harder to function effectively. Chronic stress and emotional suppression can result in burnout, physical illness, or mental health disorders like anxiety and depression.

In therapy, the body budget concept can be applied through various approaches. For example, cognitive behavioural therapy (CBT) often begins with psychoeducation, helping clients recognise how their thoughts, behaviours, emotions and physical sensations are interconnected. By understanding how stress and emotions impact their body budget, clients can identify early warning signs and make proactive choices to maintain balance and prevent exhaustion.

Acceptance and commitment therapy (ACT), another approach, helps clients ‘sit with’ uncomfortable emotions while still engaging in meaningful activities. This strategy allows clients to navigate emotional discomfort without further draining their body’s resources.

Conclusion

The brain’s primary role is not limited to thinking or intellectual activity—it is the critical organ that ensures our survival by maintaining our body budget. Understanding this function and recognising how our brains predict and regulate our body’s needs can offer us profound insights into managing stress, emotional health and overall wellbeing.

By paying attention to our body budget, we can make more informed choices that not only keep us healthy but help us thrive.

Recommended Reading: Dr Lisa Feldman Barrett, Seven and a Half Lessons About the Brain.