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

Hello readers. I hope you are well. I imagine some of you are struggling and some of you are flourishing. Life consists of both. As humans, we relish pleasurable feelings and experiences and we tend to dislike uncomfortable emotions and experiences. I get it. I am just like you. We share this. I hope that provides some comfort.

What is human development?

Human development can be described as “systematic changes and continuities in the individual that occur between conception and death, or from “womb to tomb”” (Sigelman, De George, Cunial, & Rider, 2019, p. 3).

Human development involves the continuities (i.e., what remains consistent across time) and the systematic changes (i.e., patterns of change that are expected to come in order across time) that one experiences throughout the lifespan. Based on my education, there are three domains of continuity and change: 1. The physical and biological, 2. Cognitive (i.e., mind processes/thinking), and 3. Psychosocial and emotional. Let’s open these one at a time.

Physical development includes:

• Physical and biological processes (e.g., genetic inheritance).
• Growth of the body and its organs.
• Functioning of physiological systems (e.g., brain).
• Health and wellness.
• Physical signs of ageing and changes in motor abilities.

Cognitive development includes:

Perception: the sensing of stimuli in our environment (internal and external), sending that information to the brain to be identified and interpreted in order to represent and understand our experience of the world and give it meaning. All perception involves signals that go through the nervous system.

Attention: the ability to actively (and often, involuntarily) process specific information in the environment while tuning out other details. Attention is a very interesting cognitive process because when we bring mindfulness to our thoughts we become open to the direction and attention of our mind. Remember this: where attention goes, energy flows.

Language: very broadly, Language is a communication system that involves using words (i.e., sounds arranged together) and systematic rules to organise those words into sentences and meaning, to transmit information from one individual to another. I was never very interested in language when I was studying at university however that has changed. We used language and concepts to talk to ourselves, about other people, and it is open to misinterpretation, error, and oftentimes language can be used as a means to hurt people or … bring us closer together.

Learning: very broadly defined as a relatively permanent change in behaviour, thinking, and understanding as a result of experience. Experience is everything from formal education to unique personal experience. We learn from each other, the world around us, books, movies, self-reflection and education etc. All of which are experiences.

Memory: Memory refers to the processes that are used to gather, organise, store, retain, and later retrieve information. I’m sure you’ve all seen a tv show or read a book about a person with Amnesia or Alzheimer’s disease. Imagine what your life would be like if you didn’t have the function of memory. I wouldn’t be able to type this very well, I don’t think. I wouldn’t remember my loved ones or what was dangerous in my environment. I know we all have unpleasant memories too and that may feel like a negative evolutionary by-product – however it is actually designed to protect us. Memory is finite – we actually forget a lot of stuff, or perhaps more accurately, we do not have the capacity to store and recall everything we experience.

Intelligence: I would like to reframe intelligence from what might be a common belief. Intelligence does not mean academically gifted as is considered valuable in Western society. I think Olympians and caregivers/parents have an intelligence that I do not because I haven’t learned their skills. Intelligence involves the ability to learn (i.e., sport, academics, the arts, swimming, survival, interpersonal skills), emotional knowledge, creativity, and adaptation to meet the demands of the environment effectively

Creativity: I consider creativity to be an evolutionary gift of our imagination, providing humans with the ability to generate and recognize ideas, consider alternatives, think of possibilities that may be useful in solving problems, communicating with others, and entertaining ourselves and others. Creativity can be stunted when we are struggling or caught in reactivity to external pressures or perceived stress.

Problem solving: is a process – yes, a cognitive one but also a behavioural process. It is the act of defining a problem; determining the cause of the problem; identifying, prioritizing, and selecting alternatives for a solution; and implementing a solution. Problem solving can be both creative or stress driven. I like to say whenever I am solving a problem I am also making a decision. A decision of mine is a choice. At university, our problem solving lessons were coincided with decision making which is why I think of it that way.

Psychosocial development involves:

Aspects of the self (i.e., your identity – which may change over time), and social and interpersonal interactions which include motives, emotions, personality traits, morality, social skills, and relationships, and roles played in the family and in the larger society. This is a huge area to be explored. I will endeavour to elaborate on our psychosocial development in later blogs.

In the late 1950’s, a German-American developmental psychologist named Erik Erikson created a theory for human psychosocial development across the lifespan. His theory suggests that human personality develops in a predetermined order through 8 stages of psychosocial development. See the table below:

I strongly encourage viewers, readers, and interested friends to visit Tara’s website Tara Brach – Meditation, Psychologist, Author, Teacher. So much of what I consider to be true and helpful is the wisdom I have learned from Tara Brach, an American psychologist, author, and proponent of Buddhist meditation – but more than that, she is authentic, compassionate and honest.