What Makes Us Human?

What makes humans unique in the vast tapestry of life on Earth? Is it our mind, imagination, sociability, or more?

1. The Genetics of Cognition

Human and chimpanzee DNA share up to 99% similarity, yet there’s a small genetic difference—around 1%—that sets us apart. Geneticist Walter Bodmer suggests this sliver is where our advanced cognitive abilities come from.

In 2006, biostatistician K.S. Pollard identified 49 areas of DNA that remained stable over millions of years and then evolved rapidly when humans diverged from chimpanzees. These regions may hold the secret to human intelligence. However, our cognitive abilities, like math or music, aren't purely genetic since they aren't direct results of natural selection.

Additionally, culture plays its role. A baby from an isolated jungle tribe, if raised in a modern setting, would think and act like any modern person, demonstrating that environment can shape cognitive development as much as biology.

Examples

• Comparison of human and chimpanzee DNA.
• Pollard’s discoveries of regions of rapidly evolving human DNA.
• Cultural influence on cognition demonstrated in adoption scenarios.

2. The Selfish Meme

British author Susan Blackmore suggests that beyond genes, humans are defined by their "memes"—ideas, habits, and practices passed non-genetically from person to person. Memes replicate themselves much like genes, spreading through human culture.

These memes, such as songs or traditions, evolve for their survival, not necessarily for our benefit. Memes can influence genetic evolution too. For instance, language sounds that are consistently passed down improve over time, and our brains adapt to process and produce them better, which boosts survival and reproduction.

Examples

• Catchphrases or fashion spreading across societies.
• The evolution of language sounds preserved across generations.
• Applying Richard Dawkins' "selfish gene" theory to cultural ideas.

3. Memory and Time Travel

Memory allows humans to reflect on the past and imagine the future. Psychologists Corballis and Suddendorf state this ability to "transcend time" is a key human trait. Declarative memory—our ability to consciously recollect facts (semantic) or experiences (episodic)—makes this possible.

Episodic memory, in particular, helps us plan for the future, imagine scenarios, and deal with challenges. While some animals show rudimentary planning, only humans can vividly relive memories and share them using language. Storytelling, for instance, creates scenarios in our minds that prepare us for life’s uncertainties.

Examples

• The use of stories to pass on knowledge and experiences.
• New Caledonian crows using tools for later use versus human mental time travel skills.
• Humans planning and adapting based on past experiences.

4. The Power of Imagination

Humans possess an unparalleled capacity for imagining alternate realities. Psychologist Robin Dunbar argues it’s not intelligence but imagination that sets us apart. This ability drives fields like religion, literature, and science, where abstract and "what if" scenarios are created.

Imagination is tied to theory of mind—our ability to think about others' thoughts. Children develop this ability around age four, which allows them to engage in pretend play. Apes lack this skill, operating from first-order intentionality (awareness of their own beliefs) without the capacity to think of others’ perspectives.

Examples

• Religion involving imagined deities and abstract spiritual concepts.
• Children's play with dolls or empty cups simulating tea drinking.
• Imagination applied to creating literary or scientific works.

5. From Gestures to Speech

Before humans relied on spoken language, communication came from visible gestures. This method was later complemented by facial expressions and vocal sounds, eventually giving way to spoken language, says physiologists Gentilucci and Corballis.

Non-vocal gestures bridged the gap between gestures and speech. Neurological studies have shown how movements of hands and mouth are connected. For instance, the size of an object influences how much hands and mouths open, showing their physical link.

Examples

• Primates’ gestures and their limitations for abstract concepts.
• Experiments showing synchronous hand and mouth actions.
• The evolution of language aiding communication over long distances.

6. Rationality and Spirituality

Reverend Richard Harries describes humans as "half-ape and half-angel," meaning we are both physical beings and spiritual thinkers. Our capacity for rational reflection and moral contemplation takes us beyond our biological roots.

This spiritual side fuels our pursuits, from exploring morality to seeking God. Despite no scientific proof for divinity, many are drawn to live with faith and principles. Religion often frames these quests and urges kindness, justice, and humility.

Examples

• Making big decisions by weighing pros, cons, and moral implications.
• Biblical teachings, such as “doing justice, loving kindness.”
• Humans’ enduring faith in spiritual practices despite logic-driven doubts.

7. Rewiring the Brain Through Free Will

Humans can actively change their brains and behavior, thanks to neuroplasticity. Social scientist David Hulme observes that while much of consciousness remains a mystery, we know the brain's wiring can change through conscious effort.

For instance, Jeffrey Schwartz developed a treatment for obsessive-compulsive disorder. Patients learn to understand which brain part causes their compulsions and then consciously rewire their thought patterns, reducing obsessive behaviors.

Examples

• The treatment of OCD through Schwartz's techniques.
• Studies showing the brain’s ability to rewire itself with practice.
• Changing habits by understanding the neural pathways behind them.

8. The Evolution of Bigger Brains

Geneticist Stephen Oppenheimer links bigger brains to survival during harsh Ice Age conditions. Larger brains enabled humans to adapt, find food, and develop tools and language. These traits helped early humans overcome challenges such as extreme cold and competition with predators.

Language played a large role here. Mark Baldwin theorized that learned behaviors, like language use, could shape environments and influence biological evolution, favoring the growth of larger brains.

Examples

• Archeological records showing increased brain size following ice ages.
• Early humans’ survival tied to communication and tool creation.
• Baldwin’s idea of learned behaviors influencing evolutionary paths.

9. Cooking, a Human Art

Richard Wrangham presents cooking as a defining human activity. Unlike other animals, humans cook their food, which affects digestion and caloric intake. Cooking predates even Homo sapiens, with archaeological evidence suggesting the control of fire over 1.6 million years ago.

Cooking allowed humans to develop smaller, more energy-efficient digestive systems over millennia. It also provided greater nutrition, enabling brain growth and societal advances.

Examples

• Evidence of 1.6-million-year-old campfire sites.
• Human dietary evolution tied to cooking versus raw diets.
• Nutritional benefits of cooking, supporting brain and body needs.

Takeaways

1. Appreciate your ability to learn and adapt—change your mental habits or thought patterns through mindfulness and conscious action.
2. Tap into imagination and storytelling to solve problems creatively or empathize with others’ perspectives.
3. Embrace curiosity by exploring new ideas, learning new skills, and pushing the boundaries of what you think is possible.