The Triune Brain IELTS Reading Answers

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The Triune Brain – Full Passage

Paragraph 1 The first of our three brains to evolve is what scientists call the reptilian cortex. This brain sustains the elementary activities of animal survival such as respiration, adequate rest and a beating heart. We are not required to consciously "think" about these activities. The reptilian cortex also houses the "startle centre", a mechanism that facilitates swift reactions to unexpected occurrences in our surroundings. That panicked lurch you experience when a door slams shut somewhere in the house, or the heightened awareness you feel when a twig cracks in a nearby bush while out on an evening stroll are both examples of the reptilian cortex at work. When it comes to our interaction with others, the reptilian brain offers up only the most basic impulses: aggression, mating, and territorial defence. There is no great difference, in this sense, between a crocodile defending its spot along the river and a turf war between two urban gangs.

Paragraph 2 Although the lizard may stake a claim to its habitat, it exerts total indifference toward the well-being of its young. Listen to the anguished squeal of a dolphin separated from its pod or witness the sight of elephants mourning their dead, however, and it is clear that a new development is at play. Scientists have identified this as the limbic cortex. Unique to mammals, the limbic cortex impels creatures to nurture their offspring by delivering feelings of tenderness and warmth to the parent when children are nearby. These same sensations also cause mammals to develop various types of social relations and kinship networks. When we are with others of "our kind" – be it at soccer practice, church, school or a nightclub – we experience positive sensations of togetherness, solidarity and comfort. If we spend too long away from these networks, then loneliness sets in and encourages us to seek companionship.

Paragraph 3 Only human capabilities extend far beyond the scope of these two cortexes. Humans eat, sleep and play, but we also speak, plot, rationalise and debate finer points of morality. Our unique abilities are the result of an expansive third brain – the neocortex – which engages with logic, reason and ideas. The power of the neocortex comes from its ability to think beyond the present, concrete moment. While other mammals are mainly restricted to impulsive actions (although some, such as apes, can learn and remember simple lessons), humans can think about the "big picture". We can string together simple lessons (for example, an apple drops downwards from a tree; hurting others causes unhappiness) to develop complex theories of physical or social phenomena (such as the laws of gravity and a concern for human rights).

Paragraph 4 The neocortex is also responsible for the process by which we decide on and commit to particular courses of action. Strung together over time, these choices can accumulate into feats of progress unknown to other animals. Anticipating a better grade on the following morning's exam, a student can ignore the limbic urge to socialise and go to sleep early instead. Over three years, this ongoing sacrifice translates into a first-class degree and a scholarship to graduate school; over a lifetime, it can mean ground-breaking contributions to human knowledge and development. The ability to sacrifice our drive for immediate satisfaction in order to benefit later is a product of the neocortex.

Paragraph 5 Understanding the triune brain can help us appreciate the different natures of brain damage and psychological disorders. The most devastating form of brain damage, for example, is a condition in which someone is understood to be brain dead. In this state a person appears merely unconscious – sleeping, perhaps – but this is illusory. Here, the reptilian brain is functioning on autopilot despite the permanent loss of other cortexes.

Paragraph 6 Disturbances to the limbic cortex are registered in a different manner. Pups with limbic damage can move around and feed themselves well enough but do not register the presence of their littermates. Scientists have observed how, after a limbic lobotomy, "one impaired monkey stepped on his outraged peers as if treading on a log or a rock". In our own species, limbic damage is closely related to sociopathic behaviour. Sociopaths in possession of fully-functioning neocortexes are often shrewd and emotionally intelligent people but lack any ability to relate to, empathise with or express concern for others.

Paragraph 7 One of the neurological wonders of history occurred when a railway worker named Phineas Gage survived an incident during which a metal rod skewered his skull, taking a considerable amount of his neocortex with it. Though Gage continued to live and work as before, his fellow employees observed a shift in the equilibrium of his personality. Gage's animal propensities were now sharply pronounced while his intellectual abilities suffered; garrulous or obscene jokes replaced his once quick wit. New findings suggest, however, that Gage managed to soften these abrupt changes over time and rediscover an appropriate social manner. This would indicate that reparative therapy has the potential to help patients with advanced brain trauma to gain an improved quality of life.

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The Triune Brain Passage Breakdown – Paragraph by Paragraph

Paragraph 1: Reptilian Cortex (Brain Region A) This paragraph is about the oldest brain region. It controls breathing, heartbeat, and rest — things you do without thinking. It also has a "startle centre" that makes you react fast to sudden sounds or movements. Basic social behaviour, like aggression, mating, and territory, also comes from here.

Paragraph 2: Limbic Cortex (Brain Region B) This paragraph introduces the second brain region, found only in mammals. It drives emotional bonding — caring for young, feeling grief, and forming social groups. Loneliness is also a limbic response. Reptiles lack this; mammals have it.

Paragraph 3: Neocortex (Brain Region C) – Part 1 This paragraph introduces the third and most advanced brain region, unique to humans. It handles logic, language, reasoning, and big-picture thinking. Humans can connect small lessons to build large theories — like the laws of gravity or human rights.

Paragraph 4: Neocortex (Brain Region C) – Part 2 This paragraph focuses on one key neocortex ability: delaying pleasure for future gain. A student who skips socialising to study is using the neocortex. Over time, such choices lead to major achievements.

Paragraph 5: Brain Damage: Reptilian Cortex When someone is brain dead, only the reptilian brain still works. The person looks asleep but is not conscious. This shows how basic and automatic the reptilian cortex is.

Paragraph 6: Brain Damage: Limbic Cortex Limbic damage removes the ability to feel for others. Animals with limbic damage ignore their companions. In humans, it leads to sociopathic behaviour, which is being smart but having no empathy.

Paragraph 7: Brain Damage: Neocortex Phineas Gage lost part of his neocortex in an accident. He survived but became more impulsive and crude. Over time, he adapted, suggesting that therapy can help people recover from brain trauma.

Also Check: IELTS Reading Practice Tests Based on the Latest Syllabus

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Answer Explanations

Q14 – Answer: C (Neocortex)

Statement: Giving up short-term happiness for future gains

The key phrase here is "giving up short-term happiness." This means choosing to not enjoy something now so you can benefit later.

Paragraph 4 of the passage says: "Anticipating a better grade on the following morning's exam, a student can ignore the limbic urge to socialise and go to sleep early instead."

• The student wants to socialise (short-term happiness) but chooses to sleep early instead (future gain)
• The passage directly says this ability — sacrificing immediate satisfaction for later benefit — is "a product of the neocortex"
• No other brain region can do this; the limbic cortex actually pushes you toward socialising, not away from it

So the answer is C.

Q15 – Answer: A (Reptilian Cortex)

Statement: Maintaining the bodily functions necessary for life

The key phrase is "bodily functions necessary for life" — things like breathing and heartbeat that keep you alive.

Paragraph 1 says: "This brain sustains the elementary activities of animal survival such as respiration, adequate rest and a beating heart."

• "Bodily functions necessary for life" = "elementary activities of animal survival"
• Respiration (breathing) and a beating heart are exactly what keep a body alive
• The passage also says you do not need to consciously think about these — they are automatic

This is a direct match to the reptilian cortex, so the answer is A.

Q16 – Answer: B (Limbic Cortex)

Statement: Experiencing the pain of losing another

The key phrase is "pain of losing another" — this is about grief and emotional suffering when someone is gone.

Paragraph 2 says: "Listen to the anguished squeal of a dolphin separated from its pod or witness the sight of elephants mourning their dead."

• A dolphin squealing in pain after being separated = experiencing the pain of losing another
• Elephants mourning their dead = the same idea
• The passage identifies this emotional response as a feature of the limbic cortex, which is unique to mammals

Reptiles do not show this behaviour. The answer is B.

Q17 – Answer: B (Limbic Cortex)

Statement: Forming communities and social groups

The key phrase is "communities and social groups" — this is about the need to be with others of your kind.

Paragraph 2 says: "These same sensations also cause mammals to develop various types of social relations and kinship networks. When we are with others of 'our kind'… we experience positive sensations of togetherness, solidarity and comfort."

• "Social relations and kinship networks" = communities and social groups
• The limbic cortex creates the feeling of warmth and belonging when you are with your group
• It also creates loneliness when you are away — pushing you to seek companionship

This is a limbic cortex function. The answer is B.

Q18 – Answer: C (Neocortex)

Statement: Making a decision and carrying it out

The key phrase is "making a decision and carrying it out" — this means choosing to do something and then actually doing it.

Paragraph 4 says: "The neocortex is also responsible for the process by which we decide on and commit to particular courses of action."

• "Decide on" = making a decision
• "Commit to" = carrying it out
• This is an almost word-for-word match with the question statement

The passage clearly assigns this to the neocortex. The answer is C.

Q19 – Answer: A (Reptilian Cortex) (Example Question)

Statement: Guarding areas of land

This is the example question given in the official British Council worksheet. The key phrase is "guarding areas of land" — this means protecting your territory.

Paragraph 1 says: "The reptilian brain offers up only the most basic impulses: aggression, mating, and territorial defence."

• "Guarding areas of land" = "territorial defence"
• The passage even compares a crocodile defending its river spot to a gang protecting its turf — both are reptilian responses
• This is one of the most basic impulses, driven by the reptilian cortex

The answer is A.

Q20 – Answer: C (Neocortex)

Statement: Developing explanations for things

The key phrase is "developing explanations for things" — this means building theories to understand the world.

Paragraph 3 says: "We can string together simple lessons… to develop complex theories of physical or social phenomena (such as the laws of gravity and a concern for human rights)."

• "Developing explanations for things" = "developing complex theories of physical or social phenomena"
• Only humans can do this — other mammals can learn simple lessons but cannot connect them into larger theories
• This is a function of the neocortex, which allows humans to think beyond the present moment

The answer is C.

Q21 – Answer: B (Limbic Cortex)

Statement: Looking after one's young

The key phrase is "looking after one's young" — this means caring for and nurturing offspring.

Paragraph 2 says: "The limbic cortex impels creatures to nurture their offspring by delivering feelings of tenderness and warmth to the parent when children are nearby."

• "Looking after one's young" = "nurture their offspring"
• The limbic cortex creates feelings of warmth and tenderness toward children — this is what drives parental care
• The passage also contrasts this with reptiles: "the lizard… exerts total indifference toward the well-being of its young" — reptiles have no limbic cortex

The answer is B.

Q22 – Answer: A (Reptilian Cortex)

Statement: Responding quickly to sudden movement and noise

The key phrase is "responding quickly to sudden movement and noise" — this is about fast, automatic reactions to unexpected things.

Paragraph 1 says: "The reptilian cortex also houses the 'startle centre', a mechanism that facilitates swift reactions to unexpected occurrences in our surroundings."

• "Responding quickly" = "swift reactions"
• "Sudden movement and noise" = "unexpected occurrences in our surroundings"
• The passage gives examples: jumping when a door slams, or feeling alert when a twig snaps nearby — both are the "startle centre" at work

This is a reptilian cortex function. The answer is A.

The Triune Brain passage tests more than vocabulary — it checks whether students can connect ideas, identify synonyms, and match behaviours to specific brain regions. Questions 14–22 mainly focus on understanding the core functions of the reptilian cortex, limbic cortex, and neocortex, especially in Paragraphs 1-4. Careful keyword matching and recognising paraphrased ideas are the key skills needed to answer this task accurately.