Webb Therapy Uncategorized The ‘Triune Brain’ theory by Neuroscientist Paul MacLean — an evolutionary perspective

The ‘Triune Brain’ theory by Neuroscientist Paul MacLean — an evolutionary perspective

The Concept of the "Triune Brain"

In the 1960s, American neuroscientist Paul MacLean formulated the ‘Triune Brain’ model, which is based on the division of the human brain into three distinct regions. MacLean’s model suggests the human brain is organized into a hierarchy, which itself is based on an evolutionary view of brain development. The three regions are as follows:

  1. Reptilian or Primal Brain (Basal Ganglia)
  2. Paleomammalian or Emotional Brain (Limbic System)
  3. Neomammalian or Rational Brain (Neocortex)

At the most basic level, the brainstem (Primal Brain) helps us identify familiar and unfamiliar things. Familiar things are usually seen as safe and preferable, while unfamiliar things are treated with suspicion until we have assessed them and the context in which they appear. For this reason, designers, advertisers, and anyone else involved in selling products tend to use familiarity as a means of evoking pleasant emotions.

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When our intelligent and necessary emotion – ANGER – becomes unhealthy and damagingWhen our intelligent and necessary emotion – ANGER – becomes unhealthy and damaging

The function of anger is to protect vulnerability and neutralize threat.

The threat humans cognitively perceive is almost always to the ego i.e., how we want to think of ourselves and have others think of us. Anger neutralizes ego-threat by devaluing, demeaning, or undermining the “power” of the person perceived to be threatening. Humans get angry when they don’t get what they want, when they’re disrespected, or when they perceive something is unjust/unfair. Anger, the emotion, is a chemical messenger. It communicates to us, to others, and motivates us to act, speak, do something. Healthy responses to anger include being assertive, feeling empowered, protecting ourselves and love ones from ACTUAL threat, setting boundaries with others, and making social change for justice (for example). It becomes unhealthy when we become passive-aggressive, violent, vengeful, spiteful, aggressive, resentful, sarcastic, “moody”, rude etc.

Receive the message and respond from a wise, calm place after the intensity of the emotion has past. Sometimes we have to act in the moment. Our ancestors may have required this for fight/flight survival. These days, we can generally PAUSE and calm the self before responding from a mindful and compassionate heart and mind. Remember: Hurt people, hurt people.

Acceptance and Commitment Therapy (ACT)Acceptance and Commitment Therapy (ACT)

I was recently browsing some of the units I completed for my counselling diploma – for revision. The human memory has not evolved to store, organise, categorise and recall all the large amounts of information we collect every day, nor is our memory always accurate. It’s important for counsellors and therapists to keep up to date with new approaches to counselling, and it doesn’t hurt to read over learned materials from college days. I thought I’d provide some learning about Acceptance and Commitment Therapy for readers.

Just to acknowledge the work of others, most of what is written below, I have retrieved and paraphrased from ACCEPTANCE AND COMMITMENT THERAPY Published by: Australian Institute of Professional Counsellors Pty Ltd.

Acceptance and commitment therapy, known as ACT (pronounced as the word ‘act’), is an approach to counselling that was originally developed in the early 1980s by Steven C. Hayes, and became popular in the early 2000’s through Hayes’ collaboration with Kelly G. Wilson, and Kirk Strosahl as well as through the work of Russ Harris. You can look them up on Youtube or Google if you’re interested in what they might have to say about ACT.

“Unlike more traditional cognitive-behaviour therapy (CBT) approaches, ACT does not
seek to change the form or frequency of people’s unwanted thoughts and emotions. Rather,
the principal goal of ACT is to cultivate psychological flexibility, which refers to the ability to
contact the present moment, and based on what the situation affords, to change or persist
with behaviour in accordance with one’s personal values. To put it another way, ACT
focuses on helping people to live more rewarding lives even in the presence of undesirable
thoughts, emotions, and sensations.”

(Flaxman, Blackledge & Bond, 2011, p. vii)

ACT interventions tend to focus around two main processes:

  • Developing acceptance of unwanted private experiences that are outside of personal
    control.
  • Commitment and action toward living a valued life (Harris, 2009)

In a nutshell, ACT gets its name from its core ideas of accepting what is outside of your personal control and committing to action that improves and enriches your life.

Cognitive Defusion is the process of learning to detach ourselves from our thought processes and simply observe them for what they are – “transient private events – an ever-changing stream of words, sounds and pictures” (Harris, 2006, p. 6). I think this component of ACT is incredibly beneficial if we practice it daily. I like to say, just like the function of the heart is to pump oxygenated blood around the body, one of the brain’s functions is to have thoughts. We can observe thoughts without taking them to mean more than what they are. Some thoughts are automatic, some are subconscious, and some are unconscious or preconscious beliefs that we consider to be true and factual and “rules” about how the world operates and how we have to operate in it. If someone is defused from their thought processes, these processes do not have control on the person; instead the person is able to simply observe them without getting caught up in them or feel the need to change/control them.

Acceptance is the process of opening oneself up and “making room for unpleasant feelings, sensations, urges, and other private experiences; allowing them to come and go without struggling with them, running from them, or giving them undue attention” (Harris, 2006, p. 7). Practicing acceptance is important because it encourages the individual to develop an ability and willingness to feel uncomfortable without being overwhelmed by it (Flaxman, Blackledge & Bond, 2011). It’s important to acknowledge that to accept something doesn’t mean we like it or have a passive attitude. It is to accept something exactly as it is and then we choose what to do with it. Think of the Serenity Prayer: Grant me the serenity to accept the things I cannot change, courage to change the things I can, and wisdom to know the difference.

Contact with the present moment is the concept of being “psychologically present” and bringing full attention to the “here-and-now” experience (Harris, 2009). I’d also argue that to psychologically present, we must also be aware of our physical body and the sensations within it and outside of it. Because we have the ability to think about the past and about the future, sometimes it can be difficult to stay in the present (Batten, 2011; Harris, 2009). Having contact with the present moment is essential because that it where we find out anchor and power. We have the ability to pay attention in a flexible manner to the present moment and connect with that experience rather than ruminate on past events or future possibilities (Lloyd & Bond, 2015). Some of you might say “What if I can’t stand the present moment?”. True. If you have extreme emotional experiences or have a history of trauma, it may be functional for you to use distraction or talking to someone when the present moment is “too much to take”. What we want to work towards is using healthy coping strategies in the present moment mindfully, instead of behaviours that no longer serve us.

Values, and identifying them, (i.e., what is important to the individual) is a central element of ACT because it assists clients to move in the direction of living and creating a meaningful life. One of the central goals of ACT is to help clients to connect with the things they value most and to travel in “valued directions” (Stoddard & Afari, 2014).

Committed action is the process of taking steps towards one’s values even in the presence of unpleasant thoughts and feelings (Harris, 2009). Behavioural interventions, such as goal setting, exposure, behavioural activation, and skills training, are generally used to create committed action. The ACT model acknowledges that learning is not enough, one must also take action to create change.

Self-as-context, or what I prefer to call “the observing self” or simply just our self-awareness, creates a distinction between the ‘thinking self’ and the ‘observing self’ (Harris, 2009). The thinking self refers to the self that generates thoughts, beliefs, memories, judgments, fantasies, and plans, whereas the observing self is the self that is aware of what we think, feel, sense, or do (Harris, 2009). “From this perspective, you are not your thoughts and feelings; rather, you are the context or arena in which they unfold” (Stoddard & Afari, 2014). Being aware of the observing self allows an individual to have a greater ability to be mindful and in the present moment, as they can separate themselves from the thoughts, beliefs, and memories they have.

Be Good To Yourself: The ACT Matrix | Therapy worksheets, Therapy quotes,  Psychology quotes

Mortality DeterminantsMortality Determinants


Overall Global Leading Cause of Death

  • Ischemic heart disease (coronary artery disease) – Still the #1 cause of death worldwide.
  • Followed by: Stroke, chronic obstructive pulmonary disease (COPD), lower respiratory infections, and cancer (e.g., lung, liver, colorectal).

Breakdown by Category

By Age

Age GroupLeading Cause(s) of Death
Infants (<1)Neonatal conditions, birth complications, infections
Children (1–14)Accidents (injuries), infections (low-income countries), cancers (e.g., leukemia)
Youth (15–24)Road injuries, suicide, homicide (varies by country)
Adults (25–44)Injuries (road, drug overdose), suicide, HIV/AIDS (in some countries), heart disease
Middle Age (45–64)Heart disease, cancer (esp. lung, colorectal, breast), liver disease
Older Adults (65+)Heart disease, stroke, cancer, Alzheimer’s disease

By Gender/Sex

GroupLeading Cause of Death
Cisgender MenHeart disease, cancer (lung, liver), accidents
Cisgender WomenHeart disease, cancer (breast, lung), stroke
Transgender IndividualsElevated risk from violence, suicide, and HIV/AIDS (especially trans women of color); limited large-scale data
Non-binaryInsufficient population-specific data, but risks often parallel those of trans populations or assigned sex at birth

By Race/Ethnicity (Example: United States)

GroupTop CausesUnique Issues
White (non-Hispanic)Heart disease, cancer, drug overdose
Black or African AmericanHeart disease, cancer, higher stroke risk
Hispanic/LatinoHeart disease, cancer, diabetes
Native AmericanAccidents, liver disease, diabetes, suicide
Asian AmericanCancer (leading cause), stroke, heart disease

Note: Disparities arise from systemic inequalities, access to care, and social determinants of health.


By Sexuality (LGBTQ+)

  • Limited global data, but in many regions:
    • Higher risk of suicide, mental health disorders, substance abuse, HIV/AIDS (especially among MSM and trans women).
    • Discrimination and healthcare avoidance contribute to worsened outcomes.
  • Common causes of death still include heart disease and cancer, with higher rates of premature death linked to stigma and healthcare disparities.

By Geographic Region

RegionLeading Cause(s)
High-Income CountriesHeart disease, cancer, Alzheimer’s, stroke
Low- and Middle-Income CountriesInfectious diseases (TB, HIV), maternal mortality, stroke, heart disease
AfricaHIV/AIDS, malaria, lower respiratory infections
AsiaStroke, heart disease, chronic lung disease
North AmericaHeart disease, cancer, drug overdose (opioid crisis)
EuropeHeart disease, stroke, cancer
Latin AmericaViolence (in younger adults), heart disease, diabetes

By Profession

  • Agricultural/farm workers: High injury rates, pesticide exposure, suicide
  • Construction workers: Falls, injuries, exposure to toxins (e.g., asbestos)
  • Healthcare workers: Infectious disease, burnout, mental health risks
  • Military/first responders: Combat-related injuries, PTSD, suicide
  • Office workers: Sedentary lifestyle risks (heart disease, diabetes)

Occupation-linked deaths often relate to environmental exposures, physical risks, or psychological stressors.


Conclusion:

Across almost all demographics, heart disease remains the leading cause of death, followed by cancer, stroke, and—in certain populations—accidents, suicide, or infectious diseases. However, the underlying causes (social, economic, political) differ significantly based on identity, geography, and profession.

Would you like this formatted into a chart, infographic, or specific to a country or report you’re working on?