Hi there! I’m Kate from MinuteEarth. Have you ever noticed that when you write, flip a pancake, or take pictures, you tend to use one hand more than the other? For me, it’s my right hand. Even though my left hand is similar, it struggles with these tasks. This isn’t just a human thing; many animals also have a preferred side. For example, gorillas usually use their right hand for tasks that need skill, while orangutans often use their left. Parrots hold seeds with their left foot, and Brazilian spitting spiders prefer their left forelegs when hunting.
It’s fascinating that some animals prefer their left side and some their right. But why do we have a preferred side at all? If having one “good” side is helpful, why not have two? It likely comes down to efficiency. Most animals have brains with two largely independent sides that perform different functions and control opposite sides of the body. For instance, when I write my name, neurons in the left side of my brain send signals to my right hand to guide its movements.
Building and operating that neural circuit requires time and energy, and training a limb to write well takes even more effort. To write well with my left hand, I would need a completely different circuit, which would take significantly more time and energy to develop. Instead, it’s more efficient to rely on a single circuit for writing. The more I use that circuit, the stronger the neural connections become, making my right hand even more capable and increasing the likelihood that I will use it for other tasks.
This efficiency explanation is still somewhat theoretical, but evidence from various animals suggests that having a preferred side can provide an advantage. For example, when scientists conducted a food-finding test with parrots, those with a strong side preference performed twice as well as those without. Additionally, when the task became more complex and required coordinated movements to retrieve a snack, the birds with a strong side preference excelled at finding clever solutions.
During these more complicated tasks, the “unpreferred” side also plays an important role, similar to how my left hand holds the paper while I write or steadies the camera when I take a picture. These supporting roles require their own circuitry and training to perform effectively. So perhaps our so-called “weaker” side isn’t weak at all; it’s just optimized for different tasks. Without it, we wouldn’t be able to perform various activities like hammering a nail, playing the guitar, or throwing a baseball.
Of course, there’s still the question of why I, along with most humans, would wield a sword with my right hand, while fewer would choose their left. This might be due to cultural influences or historical practices that favored right-handedness, but that’s a topic for another day!
Try using your non-dominant hand for tasks you usually do with your dominant hand, like writing your name or brushing your teeth. Record your experiences and discuss how it feels compared to using your dominant hand. This will help you understand the concept of hand preference and the role of neural circuits.
Research different animals and their side preferences. Create a presentation or poster showcasing your findings. Include examples like gorillas, orangutans, and parrots. This will help you see how side preference is common across species and understand its benefits.
Learn about the functions of the left and right brain hemispheres. Create a diagram showing which side of the brain controls which side of the body and what tasks each hemisphere is responsible for. This will reinforce your understanding of brain lateralization.
Identify tasks where your non-dominant hand plays a supporting role, such as holding paper while writing or steadying an object. Practice these tasks and reflect on how your “weaker” side contributes to completing them. This will help you appreciate the importance of both sides working together.
Investigate cultural and historical reasons for right-handedness being more common. Write a short essay or create a video discussing your findings. This will give you insight into how cultural influences can affect hand preference.
Sure! Here’s a sanitized version of the transcript:
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Hi, this is Kate from MinuteEarth. When I want to write, flip a pancake, or take pictures of hyenas, like most people, I use my right hand. Despite being similar to my right, my left hand struggles with these tasks. Many animals also have a preferred side; for example, gorillas generally use their right hand for tasks requiring dexterity, while orangutans tend to use their left. Many parrots hold seeds with their left foot, and Brazilian spitting spiders often favor their left forelegs while hunting.
It’s interesting that some animals prefer their left side and some their right, but it raises the question of why we have a preferred side at all. One way to think about it is: if having one “good” side is beneficial, why don’t we have two? It likely comes down to efficiency. Most animals have brains with two largely independent sides that perform different functions and control opposite sides of the body. For instance, when I write my name, neurons in the left side of my brain send signals to my right hand to guide its movements.
Building and operating that neural circuit requires time and energy, and training a limb to write well takes even more effort. To write well with my left hand, I would need a completely different circuit, which would take significantly more time and energy to develop. Instead, it’s more efficient to rely on a single circuit for writing. The more I use that circuit, the stronger the neural connections become, making my right hand even more capable and increasing the likelihood that I will use it for other tasks.
This efficiency explanation is still somewhat theoretical, but evidence from various animals suggests that having a preferred side can provide an advantage. For example, when scientists conducted a food-finding test with parrots, those with a strong side preference performed twice as well as those without. Additionally, when the task became more complex and required coordinated movements to retrieve a snack, the birds with a strong side preference excelled at finding clever solutions.
During these more complicated tasks, the “unpreferred” side also plays an important role, similar to how my left hand holds the paper while I write or steadies the camera when I take a picture. These supporting roles require their own circuitry and training to perform effectively. So perhaps our so-called “weaker” side isn’t weak at all; it’s just optimized for different tasks. Without it, we wouldn’t be able to perform various activities like hammering a nail, playing the guitar, or throwing a baseball.
Of course, there’s still the question of why I, along with most humans, would wield a sword with my right hand, while fewer would choose their left.
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This version maintains the core ideas while removing filler words and informal expressions.
Hand – The part of the body at the end of the arm that is used for holding and manipulating objects. – In biology class, we learned how the hand is an important tool for primates to grasp branches and food.
Brain – The organ inside the skull that controls thought, memory, feelings, and activity. – The brain is responsible for processing all the information we receive from our senses.
Animals – Living organisms that feed on organic matter, typically having specialized sense organs and nervous systems. – In our science project, we studied how different animals adapt to their environments.
Efficiency – The ability to accomplish a task with the least waste of time and effort. – The efficiency of a bird’s flight is due to its lightweight bones and powerful muscles.
Neurons – Cells in the nervous system that transmit information through electrical and chemical signals. – Neurons in the brain communicate with each other to help us think and learn.
Preferred – Liked or chosen more than others. – In psychology, we discussed how some people have a preferred learning style, such as visual or auditory.
Circuit – A pathway through which electrical signals or impulses travel. – The brain’s neural circuit helps us process complex thoughts and emotions.
Tasks – Activities or pieces of work that need to be done. – The teacher assigned us tasks to observe animal behavior in different habitats.
Connections – Links or relationships between things or people. – In the nervous system, connections between neurons are crucial for transmitting signals.
Role – The function or part played by a person or thing in a particular situation. – In an ecosystem, each species has a role that helps maintain balance and biodiversity.
