What Being Right or Left-Handed Says About Alzheimer's Risk

Did you know that the hand you use to brush your teeth or stir your coffee could influence how your brain functions? Researchers have puzzled over the differences between right-handed and left-handed individuals for decades. What they've found can help you sharpen your memory, expand your cognitive flexibility, and even reshape how you view the world. Ready to uncover the surprising science behind handedness and its impact on your brain?

Key Takeaways

• Hand Usage and Memory: People who regularly use their non-dominant hand for daily activities tend to have better episodic memory, recalling details like events, words, and faces more effectively.

• Brain Connectivity: Inconsistent handers (ICH) have a larger corpus callosum, which improves communication between the brain’s hemispheres, leading to greater cognitive flexibility and openness to new perspectives.

• Neurobics Benefits: Simple exercises like writing or brushing your teeth with your non-dominant hand can help form new neural pathways, boosting brain health and memory over time.

Could Using Both Hands Improve Your Everyday Thinking?

Nearly all Americans (87%) are right-handed, while only 13% are left-handed. Researchers have been studying this difference and conducting studies to see what it may mean for some time, but the results have been conflicting. It now seems that whether a person is right- or left-handed is not important when it comes to memory. What is important is the degree to which a person is right or left-handed. If you use your non-dominant hand at least some of the time, you may find your memory will benefit as a result.

The Edinburgh Handedness Inventory

Some people use their dominant hand almost exclusively for everyday tasks while others use their less dominant hand part of the time. 55% of Americans are considered to be strongly right-handed. They rarely use their left hand. From one to three percent are strongly left-handed. A score has been devised according to the degree to which a person uses one hand or the other. It's called the Edinburgh Handedness Inventory. Pure left- or right-handedness scores 100. On average, people score 80. A score below 80 is called inconsistent handedness (ICH). It means that at least one in ten activities is performed with the non-dominant hand. A score above 80 is termed consistent handedness (CH). CH has been found to be more prevalent among right-handers and women. Left-handers are largely ICH. Now where all this becomes interesting is the effect handedness has on the brain.

Inconsistent Handers Have Bigger Brains

The corpus callosum connects both sides of the brain and facilitates communication between them. People who are ICH have a larger corpus callosum and increased activation of the right hemisphere. This in turn leads to better episodic memory. This is the kind of memory involved with learning, storing, and retrieving information -- the ability to describe the details of a recent vacation, for instance. Several studies show people with ICH have better recall of words and paragraphs, events from their own life, early childhood memories, everyday memories, dream recall, and memories of faces. This has also been shown to extend beyond the lab into real life, where ICH people report fewer memory problems, particularly those involving conversations and conducting everyday tasks. This is true whether they are left- or right-handed. The relevant trait is whether they make extensive use of both hands. Connectivity between both hemispheres of the brain is also concerned with the capacity to update beliefs. This is considered to be a broad example of our ability to be flexible in our thinking. Studies have shown that ICH people are more likely to be open to persuasion and are better at taking other people's perspectives. People who are CH (consistent-handed) are more resistant to updating beliefs and are less likely to alter their existing viewpoints. Perhaps also relevant, people who switch back and forth between both hands are less likely to suffer from rumination or other eating disorders and less likely to suffer from dysmorphia -- a distorted view of the way they look.

Form New Neural Pathways with Neurobics

If you are strongly left- or right-handed, there's a very simple way to improve your episodic memory and increase cognitive flexibility. And that is to practice neurobics. Neurobics are brain exercises that involve unexpected stimuli. One of the most straightforward exercises to strengthen connectivity between both hemispheres of the brain is to use your non-dominant hand more often by incorporating it into everyday life. This might include eating, stirring drinks, writing, texting, drawing, dialing phone numbers, brushing teeth, opening doors, and hoovering. Virtually anything safe to do will help. Do this consistently over time, and you should notice a difference. Dr. P. Murali Doraiswarmy, head of biological psychiatry at Duke University Medical Center, says of these activities: "It's like having more cell towers in your brain to send messages along. The more cell towers you have, the fewer missed calls."

Summary

Handedness plays a surprising role in brain function and memory, but it’s not about whether you’re right- or left-handed—it’s about how much you use both hands. People who incorporate their non-dominant hand into daily activities (inconsistent handers) tend to have better memory recall, greater cognitive flexibility, and more brain connectivity due to a larger corpus callosum. This enhanced brain communication supports flexible thinking, openness to new perspectives, and resilience against rumination. Neurobic exercises, like using your non-dominant hand for tasks, can strengthen these benefits and help form new neural pathways, unlocking your brain’s full potential.

Frequently Asked Questions

• What is inconsistent handedness (ICH)?
  Inconsistent handedness refers to individuals who regularly use both their dominant and non-dominant hands for daily activities.
• How does handedness affect memory?
  People who use their non-dominant hand occasionally (ICH) have a larger corpus callosum, improving brain hemisphere communication and boosting episodic memory.

• Can switching hands really improve brain function?
  Yes, incorporating your non-dominant hand into daily tasks can strengthen neural pathways, enhance memory, and improve cognitive flexibility.

• What are some easy neurobic exercises?
  Simple tasks like writing, eating, or brushing your teeth with your non-dominant hand can help boost brain connectivity over time.

• Does this mean I should become ambidextrous?
  No, you don’t need to aim for full ambidexterity—just using your non-dominant hand occasionally is enough to reap the cognitive benefits.