Psychology Follows Physiology: The New Science of Cognitive Peak Performance
Pressed by a fantastic mentor and friend of mine recently to articulate exactly what the common thread amongst my coaching, strategies, frameworks etc was - I needed to give it some thought. Then it hit me. Everything I teach and speak about is rooted in biology and systems thinking. I believe in working from first principles, rebuilding from the ground up. So this weeks newsletter is my manifesto summarised in the phrase “psychology follows physiology”. So, what does that mean exactly?
The Backwards Approach
Every productivity guru tells you to "get your mindset right first." Fix your thoughts, they say. Visualise success. Think positive. Meanwhile, you're sitting hunched over your laptop at 2pm, running on caffeine and cortisol, wondering why your "growth mindset" isn't delivering the clarity you need for that critical decision.
Here's what they're missing: your psychology follows your physiology.
Your brain isn't some ethereal command centre floating above your body. It hasn’t evolved and formed in isolation. It's a biological organ, connected to your entire body and exquisitely sensitive to the physiological environment around it. Change your physiology, and your psychology shifts automatically. The research is unequivocal.
Think of it this way: if your mind is the operating system, your physiology is the source code. You can't debug performance issues by tweaking the user interface whilst ignoring the underlying architecture. Yet that's exactly what conventional performance advice does.
The Evidence Revolution
Embodied cognition has moved from fringe theory to mainstream neuroscience. Once dismissed as alternative thinking, embodied cognition now enjoys substantial prominence in academic circles, with researchers who take this perspective gaining widespread acceptance. Your physical state directly influences your cognitive performance through measurable, biological pathways.
Study 1: The Posture-Performance Connection
Research from the University of Auckland provides compelling evidence for the physiology-first approach. In a randomised controlled trial, participants who adopted upright posture during stress showed:
- Higher self-esteem and better mood compared to slumped participants
- Increased arousal and reduced fear responses
- Enhanced speech rate and reduced self-focus
- Measurably different linguistic patterns with more positive emotion words and fewer negative emotion words
The researchers concluded that "adopting an upright seated posture in the face of stress can maintain self-esteem, reduce negative mood, and increase positive mood compared to a slumped posture". This is biomechanics directly influencing cognitive and emotional states.
Study 2: Heart Rate Variability as Cognitive Predictor
The neurovisceral integration model demonstrates that heart rate variability (HRV) directly correlates with executive function and prefrontal cortical activity. Individual differences in HRV predict performance on tasks requiring cognitive control, working memory, and decision-making.
Multiple studies confirm this relationship (here and a systematic review here for example). Higher parasympathetic nervous system activity (reflected in HRV) consistently associates with better cognitive performance, whilst higher sympathetic activity correlates with cognitive impairment. The relationship is so robust that HRV manipulation produces measurable changes in executive function performance.
This means your autonomic nervous system state fundamentally sets the parameters for your cognitive capacity. Optimise your HRV, and you optimise your thinking.
Study 3: Vagus Nerve Stimulation and Executive Function
Recent research on vagus nerve stimulation (VNS) provides direct evidence for physiological cognitive enhancement. Transcutaneous VNS specifically improves core executive functions including inhibitory control and cognitive flexibility.
The mechanism is clear: vagal stimulation enhances prefrontal cortex function through direct neural pathways. Stimulate the vagus nerve, and cognitive performance improves measurably.
The Three Principles
This isn't about optimising around the edges, small tweaks here-and-there. It's about recognising three fundamental principles that govern peak performance:
1. Biology as Your Operating System Your physiological state sets the parameters for psychological performance. You can't think your way out of a dysregulated nervous system any more than you can think your way out of dehydration.
Your HRV can determine your cognitive bandwidth. Your posture influences your confidence and decision-making. Your breathing patterns affect your working memory capacity. Psychology follows physiology.
2. Intervention Hierarchy Start with physiological foundations before psychological strategies. Fix your HRV before you fix your mindset. Optimise your breathing before you optimise your beliefs. Otherwise you might be imposing a biological ceiling on yourself unnecessarily.
The research is clear: embodied cognition theories demonstrate that "muscular and autonomic states influence emotional responding". This means physical interventions create psychological changes and generally more reliably than psychological interventions create physical changes.
As Steven Kotler says “personality doesn’t scale, biology does”
3. Measurable Optimisation Use biological markers to track and adjust performance protocols. HRV, cortisol patterns, and cognitive test scores provide objective feedback that subjective mood tracking cannot.
Unlike psychological metrics, physiological markers offer objective precision. You can measure HRV changes within minutes. Cortisol patterns shift within hours. This creates short feedback loops that accelerate optimisation. Devices like Whoop and Oura ring offer unprecedented insight into these metrics, combined with self-initiated blood biomarker testing. This is precision peak performance.
The Systems Thinking Advantage
The human body operates as an intricate network of interconnected systems where physiological variables influence cognitive performance through complex, non-linear relationships (for an extended view on this see here). Research in systems biology demonstrates that understanding human complexity requires moving beyond simple cause-and-effect thinking to embrace the interconnected nature of biological processes.
Your autonomic nervous system doesn't operate in isolation from your endocrine system. Your breathing patterns influence your HRV, which affects your prefrontal cortex function, which impacts your decision-making capacity. These aren't separate systems you can optimise independently. They're interconnected networks that require systems thinking to understand and optimise effectively.
Physiology is the source code of peak performance.
This approach recognises that human performance optimisation must account for the complex, dynamic interactions between multiple physiological systems. When you optimise at the physiological level, psychological improvements can emerge automatically through these interconnected pathways. Furthermore, considering and optimising your physiology creates a rock solid foundation to get the most out of psychological approaches. When you start with psychology and ignore physiology, you're imposing a biological ceiling on yourself unnecessarily.
The Shift
This represents a fundamental shift from psychology-first to physiology-first performance optimisation. Instead of trying to think your way to peak performance, you engineer it through biological systems first.
The implications are profound. Every high-performer who's struggled with inconsistent energy, decision fatigue, or cognitive overload has been approaching the problem backwards. You've been trying to override your biology instead of optimising it.
Consider the executive who meditates for clarity whilst maintaining chronic sleep debt and poor nutrition. Or the leader who practices positive thinking whilst running on caffeine and cortisol. They're debugging the interface whilst ignoring the corrupted code. Bailing water out of the boat instead of plugging the leak.
The Competitive Advantage
Whilst your competitors focus on mindset and motivation, you'll be engineering biological foundations for sustained cognitive performance. Whilst they're trying to think their way to better decisions, you'll be optimising the physiological systems that enable superior thinking. You wouldn’t build a sophisticated skyscraper on weak foundations, don’t try it with your brain.
What's Next
Over the next three weeks, we'll dive deep into each of the three principles. You'll discover how to optimise your biology for sustained cognitive performance, create intervention hierarchies that actually work, and use measurable protocols to track your optimisation.
Week 1: Biology as Operating System - Understanding how physiological states set cognitive parameters
Week 2: Intervention Hierarchy - Building performance from the ground up through biological foundations
Week 3: Measurable Optimisation - Using biological markers to track and enhance performance protocols
Your physiology is the source code. Everything else builds from there.
Who am I? I am a PhD neuroscientist, turned consulting director, turned peak performance optimisation coach. I help high performers rebuild their operating system with physiology and neurobiology at the heart. Sound good? Let’s chat.