As a talent consultant, I’m often asked why two people with the same job title, similar experience, and identical training deliver very different results, i.e., why some people perform better than others at work. The short answer is: performance is a system.
It’s shaped by who a person is (values, interests, motivation, personality, ability), what they’ve mastered (experience and skills), where they work (role design, culture, leadership), and what’s happening in their lives (health, stress, sleep, caregiving).
When these pieces line up, performance compounds. When they clash, even strong performers can struggle.
Below is a summary of factors that influence performance, highlighting the complexity of human beings. We also guide leaders how to determine the causes of under-performance, when this occurs and highlight proactive ways for ensuring sound performance form the word go.
The ‘person’ factors that enable some people to perform better at work
Ability
Ability essentially measures how quickly someone learns and solves problems. Research shows general mental ability (GMA) is one of the most reliable predictors of job performance – especially in complex roles – because it accelerates knowledge acquisition and problem-solving. That doesn’t mean “clever” equals “successful,” but that people who learn faster tend to ramp up quicker and adapt better when work changes.
Personality
Personality is about the typical ways of behaving. Of the Big Five traits, conscientiousness, which is about being reliable, planful, and achievement-oriented, consistently predicts better performance across most jobs. Emotional stability also helps in many roles.
Interests
People do more (and better) when the work aligns with what they enjoy, and that is what interests are about – the activities that energise us. Large studies show that interest-job congruence leads to higher performance and persistence. If the role calls for analysis and the person loves analytical work, expect more discretionary effort and fewer motivational dips.
Values & culture-fit
When personal values, i.e. what someone believes matters at work, align with team and organisational norms – things like pace, collaboration, integrity, customer focus – performance and retention tend to rise. Misfit, on the other hand, fuels withdrawal and turnover.
Motivation
Self-Determination Theory shows motivation – what drives one – becomes more durable when three needs are met: autonomy (I have a say in how I work), competence (I can succeed and improve), and relatedness (I belong here). Teams that meet these needs see higher quality effort, resilience, and well-being. When its missing, performance takes a nosedive.
Experience & skill as a motivational force: what someone can do today
One of the most obvious causes for underperformance is inexperience or a lack of skill. Simply accumulating years of experience doesn’t constitute the acquisition of changing skill sets. The upside: you can accelerate performance with targeted training and deliberate practice rather than waiting for the calendar to tick over.
The job and the environment: How design and culture help some people perform better at work
Job design
Roles designed with skill variety, task significance, and autonomy will produce more internal motivation and higher-quality performance.
Team climate and psychological safety
If people fear blame, they hide mistakes and stop learning. However, when teams feel safe to speak up, ask for help, and try new approaches, learning behaviour increases – driving better performance over time.
Culture alignment
Beyond individual jobs, broader cultural alignment matters. A strong person-organization fit will lead to better attitudes and lower turnover; whereas a misfit can create friction that drags down performance even when ability is high.
Personal circumstances: the human factors that change
Sleep and recovery
Sleep isn’t a “nice to have” – it’s a performance variable. A lack of it impairs attention, memory, and decision quality—the very capacities modern work relies on.
Work–family conflict and stress
When demands clash at home and work, performance suffers. Flexibility, predictable schedules, and supportive supervisors help employees bring their best selves to work.
Job insecurity and financial strain
Perceived job insecurity is often associated with lower performance and engagement, and financial concerns are debilitating.
So, why do some people perform better at work?
Because their personal profile (ability, personality, interests, values) matches a well-designed job, inside a supportive culture, at a time when their life context lets them focus and recover. High performance is rarely about just “trying harder.” It’s about fit, clarity, capability, and conditions working together.
How to determine why an employee is underperforming
Given the complexity of human performance, the next logical question is: how can managers pinpoint what’s really behind an employee’s struggles?
A practical way to approach this is by working through performance issues in sequence – starting with the most likely and easiest to rule out, before moving to deeper layers of fit.
- Start with personal circumstances
If performance has been acceptable for a long period and only recently declined, chances are the cause may be personal. Rest, sleep, family conflict, or financial stress can all temporarily disrupt performance. Managers should create a safe space for honest conversations here. - Explore organisational fit
If personal challenges aren’t the culprit, it’s worth looking at the work environment itself. Job design, team climate, psychological safety, or cultural alignment may be limiting performance. If more than one team member is struggling, or if turnover is higher than peers in the industry, this is often the place to investigate. - Check for capability fit
When organisational conditions are sound but performance lags, the issue may be whether the employee has sufficient experience, knowledge, and practical skills for the role. A capability gap doesn’t mean the employee can’t succeed — it often highlights areas where development, coaching, or training are needed. - Consider person-fit factors
If the above factors check out, the final layer involves the more stable attributes of the individual: ability, personality, motivation, values, and interests. Sometimes, despite having the right skills, a mismatch at this deeper level can hold people back from thriving in a role.
By moving through this diagnostic sequence, leaders will avoid jumping to assumptions and instead gain a structured way to understand – and address – the real barriers to performance.
How can companies proactively ensure the best possible performance?
Because of the complexity of getting all of the above contributing factors aligned at the same time, perfect performance will always be elusive.
Yet, when certain HR processes are in place, effectiveness is raised. What are these?
- An HR strategy that is aligned to business objectives
- Job descriptions that support the execution of business objectives
- Clarity on the knowledge, experience, and skills required to execute roles
- Specification of the personality aspects, abilities, and interests to excel in roles
- Competent leaders who select and bring out the best in people while meeting business objectives
- Measurement of effectiveness in all aspects of the employee lifecycle and linking this to business outcomes.
Conclusion
Top performers aren’t unicorns; they’re well-matched people in well-designed roles inside well-led teams, with support for real-life demands. If you want more of them, you don’t have to gamble on “talent” or exhaust your workforce—you can design for performance.
About Competence SA
We aim to enable the most effective people strategies for our clients in alignment with their business objectives through the accurate assessment of the status quo, implementation of solutions, and measurement of success.
The solutions we offer are:
- HR Effectiveness Audits and Reviews
- Talent Management Services – recruitment, psychometrics, employee development, leadership development & succession, and performance & engagement
- Strategic Advisory and Fractional CHRO services on a retainer basis
If you want HR to be a game-changer for your business, contact us at hello@competencesa.co.za or 082 853 7456.
