The battle between nature and nurture | Irene Gallego Romero | TEDxNTU

Summary

This talk explores the complex relationship between genetics (nature) and environmental factors (nurture). The speaker discusses how genes, like those controlling lactose digestion or the likelihood of developing cancer, interact with lifestyle and environmental influences. While some traits are determined by genetics, others, like height and disease susceptibility, are heavily influenced by external factors. The speaker emphasizes that nature and nurture are not in opposition, but rather work together to shape who we are, urging the audience to reconsider oversimplified narratives about DNA's power.

Takeaways

• 🧬 You share 99% of your DNA with chimpanzees, your closest living relative.
• 🧅 Despite having complex DNA, humans have less DNA in their cells than onions.
• 🚫 Claims of single genes determining traits like crime, autism, or cancer are incorrect.
• ⚖️ The debate of nature versus nurture is more complex; neither fully dominates in shaping us.
• 🧠 Huntington's disease is a purely genetic disorder, but most traits and diseases involve both genes and life experiences.
• 🍽️ Traits like height and weight are influenced by both DNA and environment, such as nutrition.
• 🥛 Some humans can digest lactose as adults due to a genetic mutation, but this ability is pointless without access to milk.
• 🚬 Lung cancer became more common due to environmental factors like smoking, despite being a genetic disease at its core.
• 🤔 Genes respond to both each other and environmental factors, meaning life experiences also shape genetic outcomes.
• 🎨 You are not the battleground for nature vs nurture, but the canvas where they collaborate to create who you are.

Q & A

What is the speaker's main argument regarding the influence of genes?

The speaker argues that while genes (DNA) play a significant role in shaping who we are, they do not solely determine traits or outcomes like diseases, behaviors, or characteristics. Instead, both genes and environmental factors (nature and nurture) collaborate in shaping individuals.

What is the concept of 'nature versus nurture' as explained by the speaker?

The concept of 'nature versus nurture' refers to the debate over whether genetics (nature) or environmental influences (nurture) have a greater impact on a person’s development. The speaker highlights that this is not a black-and-white issue, as both factors work together rather than compete against each other.

What example does the speaker use to illustrate the role of genes in disease development?

The speaker uses Huntington's disease as an example, explaining that it is fully genetic. If someone inherits the faulty gene, they will inevitably develop the disease, which demonstrates that sometimes genes have an unavoidable influence.

Why does the speaker argue that environmental factors can sometimes override genetic predispositions?

The speaker explains that environmental factors, such as nutrition, can override genetic predispositions. For example, even if a child has tall parents, they may not reach their potential height if they experience malnutrition, showing that nurture (environment) can influence genetic traits.

How does the speaker explain lactose tolerance and its relation to both genetics and the environment?

The speaker explains that the ability to digest lactose as an adult is linked to a genetic mutation found mostly in people of European descent. However, this genetic ability would be useless without access to milk-producing animals, illustrating how genes and the environment must work together.

What role does smoking play in the development of lung cancer according to the speaker?

The speaker highlights that smoking damages lung cells, increasing the risk of developing lung cancer. While cancer involves DNA damage, the environmental factor of smoking significantly contributes to this damage, showing how nurture (in this case, smoking habits) can lead to genetic consequences.

What is the speaker's position on the concept of finding 'a gene for' specific traits like cancer or intelligence?

The speaker argues that it is misleading to say there is a single 'gene for' complex traits like cancer or intelligence. Instead, multiple genes interact with environmental factors to influence the likelihood of developing such traits, making it a much more complex process than a single gene determining the outcome.

How does the speaker refute the idea that we are simply products of our DNA?

The speaker refutes this idea by emphasizing that while DNA plays a role in shaping us, our experiences, choices, and environment (nurture) are equally important. Traits, behaviors, and diseases result from the interaction between genes and life experiences.

What analogy does the speaker use to describe how genes and the environment interact?

The speaker uses the analogy of a canvas, stating that individuals are the 'canvas' upon which nature (genes) and nurture (environment) collaborate, rather than being a battleground where one side wins over the other.

What final message does the speaker leave the audience with regarding nature and nurture?

The speaker concludes by reminding the audience that life is complex, and rather than searching for simple answers or assigning blame to nature or nurture, it’s important to recognize that both factors collaborate to shape who we are.