Reaction Time Explained: Age, Myths, and the Hidden Advantage

Summary

In this episode, we explore one of the most fundamental yet misunderstood aspects of human performance: reaction time. We often assume catching a falling object or responding instantly in sport is purely reflexive—but the truth is far more nuanced. Dr. Daniel Laby, with over 30 years of experience working with elite athletes, helps us unpack what reaction time really is, how it’s measured, and what surprising factors influence it.

We begin by breaking down simple reaction time—the fastest see–process–react loop. Unlike complex in-game decisions, simple reaction time involves a preplanned response to a visual cue. While not a mindless reflex, it’s the shortest possible cognitive pathway, critical for everything from driving to high-level sports performance.

The discussion then shifts to how we measure such a fleeting process. From Francis Galton’s 19th-century ruler drop test to modern computerized systems, each method has strengths and flaws. Even today’s tech introduces delays from sensors, software, and display refresh rates, meaning that raw scores often don’t reflect true human biology. Carefully controlled research suggests the most accurate average simple reaction time is about 210 milliseconds.

Dr. Laby’s work also uncovers key influences on reaction speed. Age clearly matters—reaction time slows by about 55 milliseconds per decade—but sex and race show no significant differences. Most surprising is the discovery of a spatial advantage: people may react faster when a stimulus appears on the opposite side of their reacting hand, likely due to how the brain processes cross-hemisphere information.

These insights have implications well beyond sports. From designing safer dashboards and alert systems to tailoring athletic training, understanding the nuances of reaction time could make a measurable difference in both everyday safety and elite performance.

Learning Points

• Simple Reaction Time Defined: A rapid see–process–react loop involving a preplanned response.
• Measuring Challenges: Traditional ruler tests are simple but imprecise; even computers introduce lag.
• Benchmark Speed: True human reaction time is ~210 ms once system delays are accounted for.
• Impact of Age: Reaction time slows about 55 ms per decade, influencing both athletes and daily activities.
• No Sex or Race Effect: Research shows no significant differences in simple reaction time between groups.
• Spatial Advantage: Faster responses can occur when stimuli appear opposite the reacting hand’s side.
• Applications: Insights can optimize training, sports strategies, and even safety systems like driving or emergency alerts.

🎧 Episode Timestamps

• 00:00 – 01:10 | Introduction: Why reflexes aren’t as simple as they seem
• 01:10 – 03:00 | Defining simple reaction time: the see–process–react loop
• 03:00 – 04:30 | Measuring reaction time: ruler drop test & early science
• 04:30 – 06:30 | Modern computer tests: hidden delays and biases
• 06:30 – 08:00 | The true benchmark: ~210 milliseconds
• 08:00 – 09:30 | Age and reaction time: slowing by ~55 ms per decade
• 09:30 – 10:45 | Myths debunked: no sex or race differences
• 10:45 – 11:45 | Spatial advantage: faster when reacting across sides
• 11:45 – 12:33 | Implications for sports, safety, and everyday life

Transcript

 We often just take our reflexes for granted. Don't we like catching something, falling off a table? Absolutely. Split-second stuff. But what if,  the tools we use to measure those quick reactions are actually, well, a bit flawed. And maybe some things we think we know about reaction speed. Like how age affects it, or even which side you see something on, or, uh.

Not quite right. That's exactly what we're diving into today. Right? Today we're doing a deep dive into reaction time. We wanna unpack what it really is, how we even try to measure something so incredibly fast and you know, uncover some surprising things that influence how quick we are. And our guide for this comes from someone with some serious credentials in this area.

Dr. Daniel Laby. Yeah. Dr. Laby. He's got over 30 years of experience working directly with Elite. Professional athletes. So his insights aren't just theory. They're based on real world, high level human performance sports vision is his specialty. Exactly. He sees this stuff in action at the highest levels.

So our mission today, to give you a clearer picture of this really crucial part of how we function, kind of a shortcut to understanding the science behind your own reactions. Let's, uh, let's get started. Okay, so the first thing to grasp, and Dr. Laby really emphasizes, this is what we call simple reaction time.

Simple reaction time. Yeah. It's not about making complex choices like, you know, deciding where to pass a ball. It's much more basic. It's just that immediate loop. You see something, your brain processes it and you make one single pre-planned response pre-planned. So like you already know what you're gonna do when the signal comes precisely.

There's no real decision-making in that moment. It's just the raw speed of that process, react pathway. Okay, so if it's predetermined, yeah. And there's no choice, is it purely a reflex then, or is there still some, you know, thinking involved, even if it's super fast? How's that different from making a split-second chase in a game?

That's a great question. Dr. Laby clarifies that even in the simple setup, it's not just a knee-jerk reflex, there is a cognitive element. It's the speed of your visual system picking up the cue. Mm-hmm. Sending that signal, your brain processes it incredibly fast, and then triggers that specific muscle action you decided on beforehand.

It's like. The absolute shortest path through the cognitive system. Right. The most direct route. Exactly. And this matters because it's fundamental. Think about just walking or driving, catching that falling last, like you mentioned earlier. Mm-hmm. Those rely on simple reactions. Mm-hmm. And as Dr. Laby knows from his work with athletes that pure speed, it's absolutely critical on the field or the court or the ice milliseconds, can literally be the difference between winning and losing.

Makes sense. Okay. So we know what it is. Conceptually. Yeah. But how do you actually measure something that happens? Well, faster than you can blink. Yeah. Measuring it is a whole other story. People have been trying for a long time. It's kind of amazing that scientists were trying to figure this out way back in the 18 hundreds.

You mentioned Francis Galton earlier. Absolutely. Galton was really a pioneer here. He basically established that reaction time could be measured, quantified scientifically. He laid that groundwork. So how did they do it back then before computers and fancy sensors? Well, one classic method. Which is still used today because it's so simple, is the ruler drop test.

Ah, I think I did this in school probably. Yeah. It's really accessible. You just need a ruler and a partner, right? You hold your fingers, uh, ready at the zero mark. Yep. Thumb and forefinger apart. At the bottom edge, your friend holds the ruler vertically, just above your fingers. Then without warning, they drop it and you snatch it as fast as you possibly can.

Exactly. You note the measurement where you caught it. Do it maybe three times to get a good average. Okay. So you end up with a distance, like 15 centimeters or something? Mm-hmm. How does that become a time? Ah, well, that involves a little bit of physics. The equations for how objects fall under gravity. We don't need to get into the weeds of the formula, but basically you convert that average distance, you measured into seconds.

And what's a typical result with that ruler test, Dr. Laby mentions that for an average adult using this method, you might get something around, say. Point one eight zero seconds. 180 milliseconds. Wow. That's still incredibly fast. When you think about 180 thousandths of a second. It is, but, and this is important, Dr. Laby himself points out that the ruler test, while neat is pretty basic. Yeah. He called it pretty elementary. Didn't he said it has a lot of inherent error. Exactly. It's good for demonstrating the concept, but it's not super precise for getting a really accurate number. Lots of variables. Okay. So if the ruler isn't the best.

Yeah. We obviously moved on to more high-tech stuff, right? Computers, we did. Since Galton's time, we've developed computerized systems that should be much more precise. Yeah. And in theory, they are. But I sense a but coming there is a but. Mm-hmm. Uh, Dr. Laby makes a really critical point here. Even these sophisticated computer systems often have their own built-in problems, their own biases and delays.

Really? I would've thought computers would be like, perfect for this. No human error. You'd think so, wouldn't you? But Dr. Laby explains, there are these tiny lags everywhere in the system. Lags. Like what? Well, think about it. The time it takes for the sensor you press to actually register the input, then the time for the software to process that signal.

Even the time it takes for the number to actually get recorded by the computer's hardware, it all adds up. Huh? Can you give an example? Yeah. He describes a common test. You watch a screen, maybe his red light turns green and you have to click a button. The instant changes, okay, I've seen those online tests, right?

So you click, but if you watch closely, you might notice a tiny, tiny delay between your physical click and when the timer on the screen actually stops, or the number is recorded. Ah, I think I know what you mean. Like the screen itself takes a moment to update exactly that delay from the button, the software, the display refresh rate, it all gets baked into your final score.

Dr. Laby calls this built-in inaccuracy. It means the number you see isn't purely your reaction time. Wow. Okay. So even our best tools aren't perfect. So if we try to account for all those computer delays, what's a more, uh, realistic number for simple reaction time? Well, that's what some recent research has tried to pin down really carefully stripping away those hardware and software effects.

Then what did they find? They found that true simple reaction times seems to be closer to about 210 milliseconds. So 0.2, one zero seconds, a bit slower than the raw number. Some systems might give you, but likely more accurate to human biology, 210 milliseconds. Okay. That's a really important benchmark. It really refines our understanding.

Alright, so we've talked about what reaction time is. Yeah. And the challenges in measuring it. Now let's get into what actually influences it. And this is where Dr. Laby’s work gets really fascinating, especially, uh, when it comes to age. Yes. This one surprises a lot of people. I was definitely surprised. We all like to think we stay pretty sharp, but Dr. Laby's research shows pretty clearly that our reaction time, well, it gets slower every single year. It does. It's a gradual decline, but it's measurable. He found it slows by about, um. 55 milliseconds. That's 0.055 seconds per decade. Actually, not per year. Per decade is more accurate based on common findings, although yearly is a way to express the trend.

Let's stick to the idea of gradual worsening. Okay? 55 milliseconds per decade. That might not sound like a catastrophe year to year. No, but think about that adding up over 10, 20, 30 years. That difference between someone who's say 18 and someone who's 40 becomes quite significant. Yeah, absolutely. Those milliseconds really start to count.

Then, not just for pro athletes, but for everyday things too. Definitely. It impacts everyone driving, reacting to unexpected situations. That subtle slowing can make a real difference. It really puts into perspective why athletes often peak physically in their twenties. But for the rest of us, just knowing this happens, maybe it encourages us to, I don't know, stay active or be more mindful as we get older.

It certainly raises awareness, doesn't it? Mm-hmm. Understanding this natural change is important, but what's also really interesting from Dr. Laby’s work is what doesn't seem to affect simple reaction time. Right. What were those findings? He found no significant difference based on sex, males versus females or across different races.

Wow. That cut against a lot of stereotypes, doesn't it? It really does. For this specific measure, simple reaction time, those factors didn't show up as significant in his findings. Yeah, a very powerful point. Okay, so age matters significantly, but sex and race don't seem to, according to this research. But then there was another finding that just seemed.

Counterintuitive, this idea of a spatial advantage. Ah, yes. This one is fascinating. It kind of messes with your intuition about how reactions should work. Totally. The finding is that you can actually react faster to something that appears on the side opposite to the hand you're reacting with. That's right.

Dr. Laby gives a clear example. Imagine you're right-handed, you're poised to react with your right hand. The research suggests you might actually react slightly faster if the signal or target appears on the left side of your visual field compared to if it appeared on the right side closer to your reacting hand.

That seems backwards. Why would that be? Does it have to do with how the brain is wired, like crossing hemispheres or something? That's the likely explanation involving how visual information crosses over to be processed by the brain hemisphere. That controls the opposite hand. But the key takeaway is that this spatial difference exists and can be measured.

So what are the implications then, especially for the elite athletes? Dr. Laby works with, it seems huge. Oh, it could be. Think about it. A right-handed hockey goalie facing a shot from their left might have a tiny, tiny speed advantage in reacting compared to a shot from their right or a right-handed basketball player reacting to a defender suddenly appearing on their left versus their right.

Exactly. Or a tennis player at the net. If this effect is consistent, it means there's this subtle built-in difference depending on where the stimulus originates relative to your dominant hand. So what do you do with that information? Do coaches start training players differently based on which side is faster?

That's the million-dollar question, isn't it? Dr. Laby certainly highlights it as an area needing more exploration. Should training focus on strengthening the slower side, or should strategies be adapted to play to the faster side? It opens up really interesting possibilities for performance optimization.

It really shows how. Dump this science goes beyond just a single reaction time number. Absolutely. It shows these factors are real and potentially exploitable in high-performance settings. It's not just theoretical, and Dr Laby seems committed to making this practical. You mentioned he even challenged people with a ruler test.

He did, yeah. In his own context, he challenged viewers to try the ruler test and offered a free vision consultation for the fastest result. It just shows his belief in applying this knowledge. That's great. Okay, so let's recap where we've landed in this deep dive. Sounds good. We define civil reaction time, that basic see, process, react loop.

We've looked at how it's measured from the uh, elementary ruler test to more complex computer systems, acknowledging the inherent errors and biases in both right. Then we got a more refined estimate of true simple reaction time being around 210 milliseconds. When you account for those system delays, then we hit the really surprising factors.

The clear impact of age with a measurable slowing over time and the lack of significant difference based on sex or race in Dr. Laby’s findings. And finally, that fascinating spatial advantage, reacting slightly faster to stimuli on the side opposite your reacting hand. All crucial insights from Dr. Laby’s extensive experience. Understanding all this isn't just for athletes chasing medals. No, definitely not. It affects all of us every day driving, walking, just navigating the world safely. It's about understanding a fundamental part of being human. These nuances really paint a clearer picture of our capabilities.

So here's something to think about. Given that these subtle factors, age spatial orientation significantly impacts something as critical as reaction time, how should this change how we design things? Hmm. Interesting question. Like should car dashboards or control panels be designed differently knowing about that spatial advantage?

Hmm. Could emergency alert systems be optimized? What small science-backed tweaks could make a real difference to safety and performance in our daily lives? Where else could we apply this knowledge? That's a great thought to leave our listeners with. How can we use this deeper understanding in practical ways?