Understand the inheritance beneath behaviour
The central message
The Architecture of an Ancient Brain completes the Why We Behave trilogy by looking further upstream. Book One considers what lies beneath behaviour, Book Two explores regulation and participation, and Book Three examines the evolutionary inheritance of systems involved in protection, prediction, connection and learning.
Evolutionary history provides a framework for asking useful questions about behaviour. It does not establish the cause of an individual child's response. Behaviour emerges from interacting influences across the brain, body, development, relationships, learning history and environment.
An ancient inheritance in a changing world
Protection can take priority
Human nervous systems developed across environments very different from many aspects of modern life. Systems concerned with detecting threat, conserving energy, maintaining connection and responding quickly remain part of contemporary behaviour.
An evolutionary perspective can help adults ask what a response may be protecting against or attempting to manage. It is not a complete explanation of behaviour, and describing a response as protective does not mean that every resulting action is acceptable.
Prediction connects the brain, body and environment
Experience shapes what comes next
The brain does not simply wait for events and then react. Previous experience contributes to expectations about what may happen next. Repeated experiences can therefore influence how readily a situation is approached as manageable, uncertain or threatening.
Prediction is useful because it allows preparation, but predictions are not always accurate. A response that once helped in a difficult situation may continue even when circumstances have changed.
The body contributes to the forecast
Prediction includes information arriving from within the body. Hunger, fatigue, pain, temperature, arousal and other internal signals contribute to the brain's assessment of what is happening and what may be required next.
This helps explain why apparently similar situations can produce different responses on different days. Behaviour alone cannot establish the biological condition that produced a response.
Safety and belonging support participation
Human development takes place in relationships. Connection, belonging and dependable support can influence whether demands feel manageable and whether a child has enough available capacity to participate.
Co-regulation is therefore not separate from learning. Responsive adults can help create conditions in which attention, communication, flexibility and recovery become more available.
Recognise cumulative stress and individual differences
Modern demands can accumulate
Stress is not defined only by one dramatic event. Noise, uncertainty, social demands, sensory load, transitions, lack of sleep, repeated effort and other pressures can accumulate across a day.
Looking at cumulative demand can therefore be more useful than searching only for the final trigger.
Recovery is part of regulation
Regulation includes the capacity to respond to demand and to recover afterwards. Repeated activation without sufficient opportunity for recovery can contribute to cumulative physiological strain.
Concepts such as allostasis and allostatic load provide ways of thinking about adaptation and cumulative demand. They do not allow a diagnosis or biological state to be inferred from behaviour alone.
Neurodiversity requires attention to both strengths and needs
Children differ in sensory processing, attention, communication, movement, learning, social experience and regulation. Support therefore needs to be responsive to the individual rather than based on assumptions about a diagnostic label.
Evolutionary accounts of autism, ADHD and other forms of neurodivergence remain hypotheses and perspectives rather than complete established explanations. Practical support should remain grounded in the child's current strengths, needs, environment and lived experience.
Create conditions in which new learning is possible
Relationships can make support dependable
Learning occurs within relationships and environments. Predictable, responsive support can help a child experience adults, routines and expectations as more understandable and manageable.
This does not require removing every challenge. It means considering whether the conditions around the challenge make participation realistically possible.
Expectations change through experience
Repeated experiences can update expectations. When a child experiences support, recovery and manageable participation, future situations may gradually become easier to approach.
Neuroplasticity provides a biological basis for change with experience, but it is not a promise that every person will develop in the same way or reach identical outcomes.
Begin with one ordinary situation
A practical starting point is one recurring situation. Look at what happens before difficulty, what the child's body and environment may be contributing, what support helps and where one small adjustment could make participation more accessible.
The aim is not to explain every behaviour through evolution. It is to widen the questions adults ask so that support can reflect the interacting influences that shape behaviour.