The following is a curated list of key terms and definitions drawn from my behavioral evaluation case studies. This guide is intended to offer clarity and insight for three primary audiences:
1) Visual handicappers using our scouting reports.

2) Horse owners, trainers, and professionals who
engage our services for psychological evaluations and 3) Students interested in learning about Herd Dynamics & Sensory Soundness.

While not every term may appear directly in a report, every category descriptor is rooted in these
foundational concepts. Understanding them will deepen your perspective and help you interpret each
horse not just by what they do, but by who they are—as seen through the lens of Mother Nature herself.
When you think differently, you see differently. This glossary is a key step towards understanding the
psychological landscape of natural herd dynamics and for seeing horses from inside out, your window in
the operating system running the machine.

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Psychological Pace Index (PPI)

The Psychological Pace Index, or PPI, tells us how long a horse can mentally handle stress and stay
focused while in motion—whether they’re walking, trotting, cantering, galloping, or racing—before they
need a mental reset.

It’s not just about how fast a horse can go, but how long they can stay mentally “on track” while doing it.
PPI measures the relationship between a horse’s mental focus and their physical movement. It gives us
insight into how well a horse can read and manage their environment as they move—and for how long
they can do that without becoming mentally overwhelmed.

A high PPI means the horse can stay emotionally balanced and mentally engaged for longer
periods—even at higher speeds—without needing help from the rider or a change in environment to
refocus.
A lower PPI means the horse reaches their stress limit faster, and will need more frequent support to stay
calm, responsive, and efficient.

Here’s the key: PPI is measured in time, not distance. And that makes a huge difference.
Distance is fixed, but time is personal. One horse might be able to stay mentally focused for just 30
seconds, even though they can physically run for two minutes. Take a race like the Kentucky Derby—
1¼ miles and roughly two minutes long. If your horse only has 30 seconds of true competitive focus in
them before needing a reset, then it becomes the jockey’s job to time those bursts of focus with
precision—to use them where it counts.

This same principle applies across disciplines—racing, cross-country, show jumping, hunter-
jumpers—you name it.

How long your horse can stay mentally in the game determines where they’ll be most successful,
and how you should train them.

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If you’re training your horse to stay focused longer than they’re naturally wired to, or asking them to
perform at their peak past their mental limit, you’re not just pushing them—you’re risking carryover
stress.
That’s when stress builds up and spills over. And instead of a horse responding to pressure with trust and
purpose—like letting controlled steam off a boiling pot—you risk triggering reactivity, shutdowns, or
long-term trauma.

That’s why, before we train, compete, or even invest— One of the most important questions I need
answered is: “How much time are we working with here?”

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Interpretative Ratio

The Interpretive Ratio is the pace at which a horse processes what’s happening around them
(psychologically) compared to how fast their body is moving (physically). Think of it as the horse’s
ability to “think faster than they move.”

A horse with a high interpretive ratio processes information quickly and smoothly while in motion,
allowing them to stay mentally ahead of their physical actions. This helps them move with fluidity,
remain emotionally balanced, and stay focused—even in high-pressure or changing situations.
The more efficient their sensory system, the more mental space—or “cushion”—they have to work
within. Horses with strong sensory soundness tend to have higher interpretive ratios, meaning their
emotional and physical responses stay synchronized, leading to better performance and fewer disruptions
in motion or behavior.

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Cushion

The Cushion is the mental “buffer zone” a horse perceives between themselves and anything in their
environment—like a jump, another horse, or a sudden distraction. It’s the space they feel they have to
think, react, or adjust before something reaches them. Think of it as the psychological workspace within
the psyche.

This cushion acts like a mental shock absorber. The more flexible and expansive it is, the better the horse
can handle stress, chaos, or surprises without getting overwhelmed. A healthy cushion helps the horse
maintain emotional control and physical fluency under pressure.

It’s not about physical distance—it’s about perceived distance measured in time and processing capacity.
Horses with a strong, elastic cushion can adapt more easily and stay mentally fresh longer. A narrow or
tight cushion creates more emotional strain, leading to quicker mental fatigue.

The cushion is also where learning happens. It’s the quiet mental space in the middle of a busy
world—the horse’s zone of comfort where they can think clearly, connect, and grow. And importantly, the
size and quality of a horse’s cushion is shaped by their interpretive ratio.

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Individual Herd Dynamic (IHD)

The Individual Herd Dynamic, or IHD, is the part of a horse’s psychology that creates a one-to-one
emotional connection—a direct mental and emotional line between the horse and a single target.
This could be a jump, a rider’s cue, a cow, another horse, or any focused point of interaction. The IHD
operates exclusively through Sensory Zone 1—the space directly ahead of the horse—making it the
most forward-driven part of their mental function.

Think of IHD as purposeful tunnel vision. When a horse is using their IHD, the rest of the world fades
away, unless something significant interrupts and is passed over to the GHD system for assessment.
This is the channel for competitive nature and expression—the core of a horse’s ability to “lock on,”
stay driven, and respond with intent and direction.

In a performance setting, a strong IHD is what allows a horse to zero in on the task at hand, block out
distractions, and keep mentally locked in from Point A to Point B. It’s not just focus—it’s emotional
energy with direction.

When the IHD is underdeveloped or easily disrupted, the horse may appear unfocused, hesitant, or overly
reactive when asked to engage in a singular task.

IHD is where competitive nature lives. It’s the mental spearhead that drives performance.

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Group Herd Dynamic (GHD)

The Group Herd Dynamic, or GHD, is the horse’s multi-sensory awareness system. It’s how they
“read the room,” stay socially connected, and manage an ever-changing environment.
Where IHD is about one thing, GHD is about everything else—and it operates through Sensory Zones 2
through 6, covering the flanks and rear of the horse.

GHD allows the horse to track sounds, herd movements, shifts in energy, and emotional cues from all
around. It’s their built-in multitasking center, and it’s what makes horses such naturally social and
responsive beings. GHD doesn’t act with pinpoint precision like the IHD—it gathers, absorbs, interprets,
and supports decisions. GHD is also the horses emotional communication headquarters.

In a natural setting, GHD is what keeps the horse safe within the herd. In a competitive setting, it’s what
gives depth, stability, and endurance to that IHD-driven competitive nature.

A strong GHD allows a horse to adapt mid-performance, respond to changes in the environment, and
maintain emotional fluency without being thrown off course. It doesn’t take the shot—but it holds the
bow steady.

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GHD is what sustains competitive expression, giving the horse the emotional and mental grounding to
stay in the game and perform with consistency. If IHD is action, GHD is feel and support.
Together, GHD supports the horse’s nature, and IHD expresses it.

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Independent Nature

A horse with Independent Nature has a rare and elite level of psychological agility. These horses have
little need for outsourcing, to look to herd mates—or even the rider—for emotional guidance. Instead,
they rely on their resilience and depth of emotional intelligence.

They are highly sensory sound, quick processors, calm under pressure, and capable of making
thoughtful, emotionally intelligent self-preservation decisions on their own.

Independent horses often show incredible poise in chaos. They can read a situation and act with intention
before the world around them even realizes something’s changed. This doesn’t make them aloof—it
makes them highly attuned.

When they’re paired with a human partner who communicates clearly and with emotional honesty, unlike
mid and lower-level herd dynamic horses where bond is more rooted in need and mutual dependency,
they form shared-leadership bonds that are truly extraordinary.

What makes them exceptional as elite athletes isn’t just their physical ability—it’s that they can fully
optimize their physical talent because their total herd dynamic processing is harmonized and high-
functioning. They have strong, fluid IHD and GHD capabilities and rarely need to “outsource” sensory
or environmental processing to peers. This means they are far less reliant on the herd or the rider for
constant redirection—they lead themselves and often see efforts to “control” this as a comprising threat
to freedom of movement, making the shared leadership concept the only privileged communication with
them.

In performance, this is the edge. In partnership, this is the magic.

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Sensory Soundness

Sensory Soundness is a measure of how well a horse can mentally connect with their environment,
handle emotional stress, and find inner contentment through a smooth-running sensory process.
A sensory-sound horse can take in the world around them without becoming overwhelmed or emotionally
fragmented. Their senses are not just “on”—they’re working in harmony, allowing the horse to stay
balanced and fluent even in challenging or unpredictable situations.

At its core, sensory soundness is about emotional regulation through efficient sensory processing. It’s
not just whether a horse can sense something—but whether they can process it in a way that keeps them
emotionally stable and physically effective. A horse with strong sensory soundness can stay calm,
aware, and purposefully expressive, even when the world gets noisy, fast, or unfamiliar.

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The Sensory Egg

The Sensory Egg is the space a horse believes they occupy—not just physically, but mentally and
emotionally. It’s the invisible bubble that surrounds the horse, forming a kind of mental shock
absorber between their body and whatever they’re focused on—whether that’s a jump, another horse, or
a human.

This space, or “egg,” is shaped by both depth perception and the horse’s sense of emotional self-
awareness. A horse may perceive themselves as being closer or farther from something than they
physically are. That difference—between perception and reality—affects how they react under pressure.
If the egg is too tight or too fragile, chaos feels closer and more threatening. If it’s elastic and strong, the
horse can absorb stress and maintain fluency, even in the face of surprises or sensory overload.

Importantly, this is where self-perception and self-awareness split. One is an assumption; the other is
grounded in emotional clarity. A well-developed sensory egg allows the horse to “herd” its own
“thoughts”, feelings, and physical actions into coordinated movement—just like a group of animals
moving as one.

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Primary & Supporting Senses

Every sensory zone of the horse’s body relies on a pair of senses working together—a primary sense,
which takes the lead in that zone, and a supporting sense, which backs it up and helps bring substance to
the incoming information.

This relationship creates a built-in checks-and-balances system, giving the horse a better chance to filter,
sort, and manage emotional or environmental stimuli without overload.
The supporting sense also acts as a bridge—helping information pass between zones when needed,
especially when a single zone is overloaded or dealing with diverse stimuli. This bridging process is
critical for Sensory Lead Changes (see below).

When the primary and supporting senses in a zone are efficient and well-balanced, the horse is more
emotionally stable and less reliant on others for help—resulting in smoother transitions, better focus, and
a deeper ability to self-regulate.

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Sensory Sequence

The Sensory Sequence is the six-step process that blends what the horse sees, hears, or feels in the
physical world with how they emotionally respond to it. It’s how the horse turns external information
into internal reaction, merging the physical world with the emotional horse.

1. Survey – The horse notices something.
2. Orient – The horse adjusts attention toward it.
3. Investigate – The horse seeks more detail or clarity.
4. Absorb – Emotional energy begins to form around the input.
5. Interpret – Meaning is assigned; judgment is made.
6. Respond – The horse reacts with movement or expression.

Every moment of a horse’s day runs through this cycle. When the sequence runs smoothly, the horse stays
emotionally present and physically coordinated. But if one step gets rushed, skipped, or overloaded,
confusion or reactivity can take over, especially under stress.

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Standard Aspect Zones (SAZ)

The horse’s sensory system is made up of six Standard Aspect Zones, or SAZ—each one covering a
different part of the horse’s body and surrounding space. These zones are:

 Zone 1: Forward (frontal vision, governing dynamic: IHD)
 Zone 2: Front-left (governing dynamic: GHD)
 Zone 3: Front-right (governing dynamic: GHD)
 Zone 4: Rear-left (governing dynamic: GHD)
 Zone 5: Rear-right (governing dynamic: GHD)
 Zone 6: Behind (governing dynamic: GHD)

Each zone functions like a puzzle piece, equipped with its own emotional tools and sensory
responsibilities. When a horse can process information well in all six zones, they don’t need to rely
heavily on the herd or the rider to make decisions. But if one or more zones are weak or inefficient, a
sense of isolation and exposure fills the void and the horse will “outsource” processing to peers—(answer
the question they cannot answer) lest they become overwhelmed when too much comes in at once. This
defines mutual dependency and is these vulnerabilities are in reality the tensile strength of herd structure
and connected hierarchy.

Just like people are stronger with one hand than the other, horses can be more fluent in one zone and
more vulnerable in another. That’s why recognizing zone-based imbalances is key to understanding
behavioral quirks, emotional struggles, or performance inconsistencies.

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SLC: Sensory Lead Change

A Sensory Lead Change (SLC) is like a baton pass between sensory zones. When a stimulus enters one
zone but needs further processing in another, the information is passed along—from the primary sense of
one zone to the supporting sense of another. This process is what allows a horse to process stimuli
when in motion or stimuli that is moving, and helps them maintain space awareness, think of schooling
fish or flocking birds.

This internal handoff keeps the Sensory Sequence flowing without interruption. If the pass doesn’t
happen smoothly—or gets dropped—the result can be confusion, hesitation, or emotional instability.

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SLCs are especially vital during quick transitions or moments of uncertainty. A horse that has strong
sensory zone connectivity and can perform clean SLCs is more likely to remain emotionally sound,
coordinated, and responsive—even in fast-paced or chaotic situations.

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Sensory Map Sample:​​​​​​​​​​​​​​​​​​​​​