How to tell if you're actually left-handed?: The subtle science of hand dominance

September 30, 2025 •

3 min read

According to a 2020 meta-analysis, approximately 10.6% of the population is left-handed. If you've ever wondered about your own hand dominance, finding out how to tell if you're actually left-handed involves more than just how you hold a pen, exploring a range of behaviors and subtle instincts.

Quick Summary

Examine common tests and subtle clues to determine if you are truly left-handed, mixed-handed, or ambidextrous. Learn to differentiate between natural preference and learned habits and understand the science behind hand dominance.

Key Points

Instinctive Actions: Pay attention to unthinking, spontaneous actions like throwing, clapping, or folding your arms to reveal your natural hand preference.
Timed Performance Tests: Perform speed and neatness tests, such as writing the alphabet with both hands, to measure actual dexterity and dominance objectively.
Everyday Observational Clues: Watch for habits like ink smudges on your hand, how you wear your watch, or your comfort with standard right-handed tools.
Distinguish Handedness Types: Understand the difference between true left-handedness, mixed-handedness (using different hands for different tasks), and rare ambidexterity (equal skill with both).
Address Childhood Switching: If you were forced to switch hands as a child, be aware of signs like fatigue or discomfort with your 'trained' hand, which may indicate a suppressed natural tendency.
Observe Whole-Body Laterality: Consider other forms of laterality, like which foot you use to kick or which eye you instinctively use to sight, for a more complete picture.

The Instinctive Clues: Moving Beyond the Pen

While writing hand preference is often the first indicator, it isn't always reliable, especially for those who were forced to switch hands as children. To find out for sure, it's best to observe your unconscious, instinctive actions.

Simple Tests for Laterality

To test your instinctive tendencies, perform these quick, unconscious tasks:

Clapping: Which hand is on top when you clap naturally? Left-handers typically have their left hand on top.
Arm Folding: When you fold your arms, does your left arm go on top? This can indicate left-handedness.
Interlocking Fingers: Which thumb is on top when you clasp your hands? Often the left thumb for left-handers.
Picking Up an Object: Note which hand you instinctively reach with when someone offers you an item.

Performance-Based Assessments

Timed performance tests can provide a more definitive answer by measuring dexterity differences between hands.

The Alphabet Test

Write the alphabet A to Z with your right hand as fast as you can.
Repeat with your left hand.
Compare speed and neatness. Left-handers are usually faster and neater with their left hand. Similar performance might suggest ambidexterity.

Drawing and Coloring

Color inside two identical simple drawings, one with each hand. The hand that produces the neater result is likely dominant.

Everyday Clues and Habits

Daily habits can also reveal your natural handedness.

Observational Indicators

Left-handers often experience ink or pencil smudges on the side of their left hand. Many lefties wear their watch on their right wrist, and difficulty with standard right-handed tools is common. Left-handed individuals might prefer carrying a bag on their right shoulder.

Understanding the Nuances: Mixed-Handedness and Ambidexterity

Handedness exists on a spectrum. Left-handed individuals consistently prefer the left hand for skilled tasks, while right-handed individuals prefer the right. Mixed-handed or cross-dominant people use different hands for different tasks, like writing left but throwing right. This is more common than true ambidextrousness, which is the rare ability to perform tasks with equal skill in both hands.

How to tell if you're actually left-handed: A Comparison


Trait / Task	Strongly Right-Handed	Strongly Left-Handed	Mixed-Handed	Ambidextrous
Writing Hand	Consistent right	Consistent left	Varies by task, possibly right due to forced switching	Writes equally well with both
Throwing a Ball	Right hand instinctively	Left hand instinctively	May use different hands for different types of throws	Equal skill with both hands
Clapping Motion	Right hand on top	Left hand on top	Inconsistent or less pronounced preference	Inconsistent or equal
Arm Folding	Right arm over left	Left arm over right	Inconsistent	Inconsistent
Using Scissors	Right-handed scissors feel natural	Struggles with right-handed scissors; prefers left-handed or adapts	Adapts to tool; may use both hands depending on the tool	Proficient with both hand types
Fine Motor Skills (e.g., drawing)	Better control with right	Better control with left	Varies by task and learned habit	Excellent control with both
Hand Smudges (Writing)	None	Ink or pencil smudges on the side of the left hand	Depends on writing hand	None or inconsistent

The Aftermath of Forced Switching

Forced switching of handedness in childhood was once common. Signs of a converted left-hander include less fluid right-handed writing, discomfort during intensive tasks, and sometimes reverting to the left hand for spontaneous actions. Observing these patterns can offer insight into a suppressed natural preference.

The Biological Basis for Laterality

Handedness is a complex trait influenced by genetics and environment. It is linked to brain hemisphere asymmetry; the left hemisphere, which controls the right side of the body and language in most people, may explain the prevalence of right-handedness. However, the neurological basis in left-handers is more varied.

Conclusion: Embracing Your Natural Side

Ultimately, figuring out how to tell if you're actually left-handed is about understanding your natural instincts versus learned habits. Discovering your handedness provides insight into your unique makeup. Embracing your natural side can lead to greater comfort and efficiency in daily tasks.

For more detailed information on handedness and brain asymmetry, the Laterality: Asymmetries of Body, Brain and Cognition journal provides a wealth of expert research.

Frequently Asked Questions

Observing instinctive, unpracticed actions like which hand you use to throw a ball or fold your arms is often more reliable than just your writing preference, as writing is a learned skill that may have been influenced by past conditioning.

Yes, there is a complex genetic component to handedness, but it is not a simple Mendelian trait. While left-handed parents are more likely to have left-handed children, the inheritance pattern is not a guarantee.

Mixed-handedness, also known as cross-dominance, is when a person uses different hands for different tasks, not having a single, strong preference across all activities. For example, a person might write with their left hand but prefer to use their right hand for throwing.

No, ambidexterity means having equal skill and dexterity in both hands for the same tasks. Mixed-handedness is about preference, where different hands are used for different tasks, but not necessarily with equal skill.

You might exhibit signs of a converted lefty, such as less fluid or messy handwriting with your 'trained' hand, slower writing speed, and a tendency to revert to your left hand for spontaneous or non-writing tasks. Observing these signs can help you uncover your natural preference.

While it's possible to train yourself to become more skilled with your non-dominant hand, achieving true natural ambidexterity (equal skill with both hands) is very rare. Many left-handers become more proficient with their right hand out of necessity in a right-handed world.

Research has explored various potential links between handedness and certain health characteristics, such as neurological conditions or specific skill advantages in sports. However, the connections are complex, and handedness is not a determining factor for overall health.

No, handedness does not determine personality traits. While some studies have explored statistical correlations, there is no scientific basis to suggest that being left-handed or right-handed dictates your character or behavior.