We like to believe promotions are mainly based on candidates’ competence. In reality, they often hinge on a more implicit question: “who has the potential for what’s next?” And that’s exactly where things get tricky. In a recent study published in Personnel Psychology, Giverny De Boeck, Melvyn R. W. Hamstra, Nicky Dries, and Prisca Brosi show that employees aged 45 and over are disadvantaged not because they perform worse, but because internal judgments about their potential work against them.
Their demonstration combines field data and experiments. On one hand, they analyze data from 842 employees in a financial organization, where managers rate performance and potential, and then track who gets promoted the following year. The result: age significantly reduces promotion chances, and this effect is driven mainly by internal judgments about potential, while performance does not explain the outcome in any meaningful way. On the other hand, they run experiments where only age varies in a fictitious profile. With identical content, a 48-year-old employee is seen as having less potential than a 28-year-old. And when evaluators are required to explain their reasoning, the effect disappears.
The mechanism is fairly straightforward. Judging potential means imagining what someone could do in the next one to five years. These are inherently uncertain judgments, which push managers to simplify and rely on cognitive shortcuts. Age becomes a quick signal, tied to stereotypes about adaptability or learning. No one explicitly penalizes age, but it still enters the decision indirectly. And because these internal judgments carry significant weight in promotion decisions, the bias carries through.
The contribution of the study is to shift the focus toward the process. This is not just about individual bias, but about how organizations structure these judgments. The authors show that holding managers accountable for their reasoning, clarifying the criteria used, and structuring the process more rigorously promote more systematic thinking and reduce age effects. In other words, the issue is not that organizations consider potential, but that too little effort is made to assess it in a disciplined way.