Why the Last Candidate Rarely Gets the Job

You have five candidates and one day. By the fifth conversation you are still asking the right questions. You are still nodding in the right places. But somewhere in the back of your head, a quieter voice has started asking a different question, which is roughly: how much longer is this.

You would never admit that influenced your scoring. And you probably do not believe it did.

The research says otherwise.

Sequence Position Shapes Judgement

Researchers analysing ten years of MBA admissions interviews found that interviewers' scores were shaped by who they had already seen that day. After a run of strong candidates, the next applicant was rated more harshly than their performance warranted. The effect was consistent enough to show up across thousands of interviews.

A separate study of asylum judges, loan officers, and baseball umpires published in the Quarterly Journal of Economics found a similar pattern of sequence dependence in high stakes, repeated decisions. And the parole board study from PNAS that most people have now heard about found that favourable rulings declined steadily across successive cases before recovering after a break.

None of these professionals were careless. All of them were making decision after decision after decision.

What Is Actually Being Depleted

For years the explanation was willpower, framed as a battery that runs down. That model has been challenged heavily and does not hold up as cleanly as it once did.

The more current picture is physiological. Research suggests that sustained decision making is associated with glutamate accumulation in prefrontal synapses. Glutamate is the brain's main excitatory neurotransmitter, and in excess it appears to create something like a biological traffic jam that interferes with the signalling the prefrontal cortex depends on to weigh evidence carefully. The 2022 Current Biology work found that people in this state shifted toward lower effort choices without noticing any change in their own reasoning.

That last part matters most for hiring. Decision fatigue does not feel like fatigue. It feels like clarity. It feels like you have finally figured out what you are looking for.

What To Do About It

Score each candidate before you see the next one, and score against a written standard rather than against the person you just met. Cap the number of substantive evaluations you run in one block. Separate structured interviewing from final deliberation, because those are two different cognitive jobs and stacking them multiplies the load.

And protect the decision capacity itself. Numin is designed to support the brain's natural glutamate clearance process, so the fifth conversation gets closer to the same judgment as the first. 

Make every decision count. Especially the ones about people.