The Three-Body Problem: Why Your Best People Interventions Keep Failing

Sarah was the perfect candidate. Brilliant analytical mind, stellar track record, glowing references. She'd thrived in similar roles at two previous companies. Same industry, same challenges, same stakeholder dynamics. When she joined my client's leadership team, everyone expected another success story.

Six months later, she was struggling. Not dramatically failing, just... different. Less innovative, more cautious, increasingly frustrated. The role hadn't changed. Her capabilities hadn't diminished. Yet somehow, in this new environment, her behaviour had shifted entirely.

What had changed? Her new office was located next to the executive floor instead of embedded within her team. But here's the thing—that wasn't the difference. It was part of a complex interaction that fundamentally altered what psychologists call the affordance of her leadership system.

This story illustrates what physicists have known for over a century: complex systems don't behave the way we expect them to.

When Simple Rules Create Impossible Predictions

In the 1680s, Newton's laws of motion could perfectly predict the orbit of any planet around the sun. Two bodies, elegant mathematics, predictable outcomes. Science felt wonderfully linear.

Then astronomers tried to map the Moon's orbit around Earth while Earth orbits the Sun. Three bodies. Same laws of physics. Suddenly, the mathematics became impossible.

This became known as the three-body problem: can you predict the motion of three objects that are all gravitationally attracted to each other? The answer, proved definitively by Henri Poincaré in the 1890s, is no. Not because we lack computing power or mathematical sophistication. Because the system itself resists prediction.

Three bodies create what we now call chaotic dynamics. Tiny changes in starting conditions—move one object by a fraction of a millimetre—can completely alter the system's behaviour over time. The motion follows precise physical laws yet becomes fundamentally unpredictable.

Poincaré's discovery didn't just solve an astronomy puzzle. It revealed something profound: complexity can emerge from simplicity, and predictability has inherent boundaries.

The Workplace Three-Body Problem

Behaviour in organisations follows a similar pattern. Every action emerges from the interaction of three components: Someone (the person), Somewhere (the environment), and Something (the task).

Like gravitational bodies, these three elements continuously influence each other. But here's where it gets interesting: what matters isn't the individual characteristics of each component, but the affordances that emerge from their interaction.

Affordances are the possibilities for action that a system offers. They exist neither in the person alone nor in the environment alone, but in the relationship between them. A door handle affords opening to someone with hands, but not to someone without. The affordance isn't in the handle (a property of the environment) or in having hands (a property of the person)—it's in the interaction between them.

Sarah's behavioural shift wasn't caused by her office location. The environmental change fundamentally altered the affordances available to her leadership approach.

The Collapse of Leadership Affordances

In her previous roles, Sarah's system afforded informal influence-building. She could have spontaneous conversations, pick up on team dynamics through casual observation, build relationships through proximity, and establish credibility through consistent availability. These weren't just her preferences—they were the action possibilities that emerged from the interaction between her leadership style (someone), embedded office locations (somewhere), and relationship-dependent tasks (something).

Her new environment offered completely different affordances. The system now enabled formal executive interactions, strategic oversight from distance, hierarchical influence, and structured communication. The same person, with the same formal responsibilities, but subtly different possibilities for action.

The problem wasn't that Sarah lacked the skills for her new environment. The problem was that her most developed leadership behaviours were no longer afforded by the system. Meanwhile, the behaviours that were afforded felt foreign and uncomfortable, creating a feedback loop of diminishing confidence and effectiveness. Sarah was out of calibration with her environment.

The Reductionist Trap

Traditional change management approaches this complexity using the wrong principles. They assume that if we can identify the root cause of a problem, break it down into manageable components, and fix each piece systematically, we can solve the whole system. This works in simple closed loop systems like a manufacturing floor.

This thinking feels logical. It's how we approach mechanical problems—identify the broken part, replace it, machine works again. It's how we've been taught to solve business problems since the industrial revolution. Taylorism and the industrial revolution maximised these principles.

But the three-body problem reveals why this approach fails in complex systems. Emergence means that the behaviour of the whole system cannot be understood by studying its parts in isolation. The interesting dynamics—the things that really matter—only appear when all three components interact.

More critically, traditional approaches focus on individual dispositions rather than system affordances. We analyse Sarah's personality traits, competency gaps, or motivational issues (someone). We examine role requirements, task complexity, or performance standards (something). We assess office layouts, team structures, or cultural norms (somewhere).

But studying components individually misses the fundamental insight: affordances emerge from the interaction between all three elements.

You can measure each celestial body's mass, velocity, and trajectory in perfect detail, but you still won't be able to predict how they'll behave when they interact with two others. The unpredictability doesn't come from incomplete knowledge of the components. It comes from the interaction itself.

Consider how this plays out in typical organisational interventions:

Root Cause Analysis assumes there's a single factor (or small set of factors) creating the problem. But in complex behavioural systems, causation is circular and emergent. Sarah's struggles weren't caused by her location, her capabilities, or her role requirements. They emerged from the collapse of previously available affordances and the emergence of new ones that didn't match her developed capabilities.

Component-Based Solutions try to fix individual dispositions while ignoring system affordances. We send people on leadership courses (changing the someone), redesign processes (changing the something), or restructure teams (changing the somewhere). Then we wonder why the improvements don't stick—because we haven't addressed the affordances that emerge from their interaction. Complex systems are surprisingly resilient to competent dominant changes.

Linear Project Planning assumes we can predict outcomes by controlling inputs. We create detailed change plans with milestones, deliverables, and success metrics. But complex systems don't follow project timelines. They evolve according to their own internal dynamics, creating and destroying affordances in unpredictable ways.

The three-body problem shows us that you cannot deconstruct complex interactions without destroying what makes them complex. The moment you separate the components to study them individually, you lose the very thing you're trying to understand—the affordances that emerge from their interaction.

What Might Have Maintained Equilibrium?

Understanding emergence means recognising that small adjustments in any of the three elements could have preserved or recreated the affordances that made Sarah effective:

Someone modifications that recreate affordances:

- If Sarah had developed comfort with formal, scheduled interactions that still enabled relationship-building

- If she had learned to leverage hierarchical positioning for informal influence

- If she had adapted her leadership style to work through structured rather than spontaneous interactions

Something adjustments that preserve affordances:

- If her role had included regular team presence requirements that maintained informal interaction opportunities

- If her responsibilities had been redesigned to leverage executive proximity while preserving team connection

- If her success metrics had valued the relationship-building that her environment now made more difficult

Somewhere fine-tuning that restores affordances:

- If the executive floor had included collaborative spaces that afforded both formal and informal interactions

- If technology had been implemented to recreate the spontaneous connection affordances she had lost

- If office culture had evolved different norms that afforded cross-floor relationship-building

The key insight is that affordances emerge from the entire system interaction. You can't create them by changing individual components in isolation. They require conscious design of the whole system to support the behaviours you want to see.

Why This Matters for Practitioners

Most people interventions assume that changing individual dispositions will change behaviour. We believe that if we can improve someone's skills, knowledge, or motivation, we can predict and control their performance. In some circumstances this may be sufficient. But many of us in HR know these are not sufficient solutions to the organisational challenges we face today.

The three-body problem suggests this assumption is fundamentally flawed. In any system more complex than two bodies, affordances matter more than dispositions. The lift-ability of a shopping bag depends more than just how much it weighs.

Consider how often we've seen:

- Leadership development programmes that work brilliantly in one division but fail in another—because they focus on developing individual capabilities rather than designing system affordances

- High performers who struggle when promoted or moved to different teams—because their most effective behaviours are no longer afforded by the new system

- Cultural change initiatives that succeed in some locations while stalling elsewhere—because they ignore how local affordances either support or constrain desired behaviors

- Coaching that transforms some individuals but has little impact on others—because individual development disconnected from system design creates capabilities that can't be exercised

We typically explain these inconsistencies by looking for differences in individual dispositions. But often, the explanation lies in system affordances—what possibilities for action actually exist in each specific context.

More fundamentally, we miss that behavioural outcomes emerge from the dynamic interaction between someone, somewhere, and something in ways that create or constrain affordances for effective action.

The Limits of Prediction

This doesn't mean people interventions are pointless. Weather forecasters can't predict exactly where a butterfly will be in three weeks, but they can tell you it will probably rain tomorrow.

Similarly, we can't predict precisely how individuals will behave in complex organisational systems, but we can:

Focus on affordance design rather than disposition change. Instead of trying to fix people, design systems that afford the behaviours you want to see. Create environments where effective action is not just possible but natural.

Map system affordances before intervening. Before implementing change, understand what possibilities for action currently exist and how your intervention might alter them. Ask not just "what skills does this person need?" but "what does this system afford?"

Embrace experimentation over planning. Like Poincaré's mathematical proofs, some affordances simply can't be designed—they must be discovered through small experiments and rapid learning cycles.

Look for affordance patterns, not individual predictions. While specific behavioural outcomes remain unpredictable, you can often identify which system configurations consistently afford certain types of action.

Acknowledge complexity honestly. Stop promising linear outcomes from complex interventions. Help leaders understand that changing affordances involves irreducible uncertainty.

The Practitioner's Paradox

Here's the paradox every HR professional faces: organisations demand predictable results from inherently unpredictable systems. They want guaranteed ROI from leadership development, measurable outcomes from culture change, and linear progress from performance improvement.

The three-body problem teaches us that this demand is not just unrealistic—it's scientifically impossible. Complex systems, whether planetary orbits or workplace behaviours, resist the kind of prediction and control that traditional management thinking requires.

This isn't failure. It's physics.

Sarah's struggle wasn't a failure of recruitment. It was an inevitable result of system dynamics that no amount of planning could have fully anticipated. The question isn't how to prevent such disruptions, but how to design systems that afford multiple pathways to effectiveness and can adapt dynamically when affordances shift.

The question isn't whether we can eliminate unpredictability in human behaviour. We can't. The question is whether we can design affordances that work with complexity rather than against it.

What affordances does your current system offer for the behaviours you want to see?

What possibilities for action are accidentally constrained by how you've designed the interaction between people, environment, and tasks?

Understanding complexity doesn't excuse poor practice—it demands better practice. Practice that focuses on system-wide affordances rather than individual dispositions. Because even if we can't control the orbit, we can still design the gravitational field.​​​​​​​​​​​​​​​​