There is a great deal of research on leadership effectiveness and leadership styles in the workplace. Some of these studies are contradictory or inconclusive. At best, many rely on constructs that are difficult to measure cleanly. Nevertheless, we still show up at work every day, leading in various ways and at different levels, trying to move our organisations forward and achieve common goals.

In one episode of The SMB Investor podcast, a guest reflected on the types of people they had successfully worked with across different businesses. After examining various factors, they arrived at a simple conclusion: the single unifying trait was that these individuals were happy people. Conversely, when collaborations failed, it was often because those individuals were not.

“The team that you have, that you inherit [post-acquisition], is going to determine a lot of what you work on when you get there… So, the number one thing we learned across the last decade, across my partners in my many dealings, is when we’re hiring people, everything comes down to basically one variable, and it’s ‘are they happy people or are they sad people?’ … Every time we hired someone where they ended up being a problem down the line… it came down to them not being happy in some way, and that mentality kind of pervading the rest of the company.”

From The SMB Investor: Ep. 30- Sales and Growth Strategy for Small Business Buyers

This raises an uncomfortable question: what leadership style could have helped a leader successfully lead a persistently unhappy person?

It is difficult to identify one. Different approaches may be attempted—more direction, more support, more autonomy—but the outcome is often limited. The constraint does not appear to be the leader’s style alone, but something more fundamental about the individual being led.

This is where Situational Leadership Theory becomes relevant. Many people intuitively believe that effective leaders adapt their style to the individual in front of them. The promise is simple: match your approach to the person, and performance will follow.

The research, however, is less certain. Empirical tests of the theory suggest that adaptation alone is not enough and may not even be the primary driver of performance.

Situational Leadership Theory – The Core Idea

Situational Leadership Theory begins with an idea that feels almost too obvious to question: there is no single best way to lead. Instead, effective leadership depends on the person being led. A good leader, in this view, is not defined by a fixed style, but by their ability to adjust—shifting how they behave depending on who is in front of them and what is required.

At a surface level, this is compelling. It aligns with everyday experience. People are different, so it follows that they should be led differently. The theory takes this intuition and formalises it into something more structured.

How the Theory Works

The structure itself is deceptively simple. Leadership behaviour is reduced to a combination of direction and support—how much guidance a leader provides, and how much relational or emotional backing they offer alongside it. From this, four broad approaches emerge, ranging from highly directive to highly hands-off.

Opposite this sits the follower. Here, the theory introduces the idea of “readiness”—a blend of competence and commitment. Some individuals may lack the skills but be eager to learn. Others may be capable but disengaged. A few may have both the ability and the motivation to operate independently.

The central mechanism of the theory is the pairing of these two sides. Different levels of readiness are meant to call for different leadership approaches. Someone inexperienced but enthusiastic should be guided closely. Someone highly capable and committed should be trusted with autonomy. Between these extremes, the leader adjusts accordingly.

The promise is clear: if the leader gets this match right, performance will improve.

Where the Intuition Meets Evidence

This is where the theory becomes more interesting—and more uncertain.

When researchers, including Robert P. Vecchio, began to test this idea empirically, they focused on its core claim: that effectiveness is driven by the interaction between leadership style and follower readiness. In other words, not just that leadership matters, or that people differ, but that the precise alignment between the two is what produces better outcomes.

The evidence does not strongly support this.

Across studies, the expected advantage of “matching” is inconsistent. In many cases, it does not appear at all. Leaders who adjust their style to fit a follower’s supposed level of readiness do not reliably achieve better performance than those who do not.

Instead, something simpler emerges. Leadership behaviours themselves have direct effects. Some ways of leading are generally more effective than others. At the same time, the characteristics of the follower—how capable they are, how motivated they are—also exert their own influence. But the specific pairing between the two does not seem to carry the weight the theory assigns to it.

The Problem Beneath the Model

Part of the difficulty lies in the variables the theory depends on.

“Readiness” is not a single, stable attribute. It combines skill, confidence, and motivation—factors that do not always move together, and which can shift depending on the task or context. Measuring it cleanly is challenging.

On the other side, leadership behaviour is not as neatly divisible as the model suggests. In practice, leaders do not operate in discrete modes. They blend instruction and support continuously, often without conscious calibration.

What the theory presents as a clean matching exercise becomes, in reality, far more ambiguous.

What the Research Leaves Us With

Situational Leadership Theory captures something important. It recognises that people are not identical, and that leadership should not be rigid. That intuition survives scrutiny.

What does not hold as strongly is the idea that effectiveness comes from systematically matching a defined leadership style to a defined level of follower readiness. The mechanism is too imprecise, and the evidence too inconsistent, for that claim to stand on its own.

Which brings us back to the earlier observation.

If the defining difference between successful and unsuccessful hires is whether they are broadly happy or unhappy, then leadership style is operating downstream of a more fundamental variable. No amount of adjustment, more direction, more support, more autonomy, can reliably turn a persistently unhappy individual into a high-performing one. The limits of leadership are reached sooner than we might like to admit.