Rethinking Interviews: What Really Predicts Job Success?
When it comes to hiring, many businesses continue to rely heavily on interviews, especially informal ones, to assess whether a candidate will succeed. But research shows that interview performance alone is a moderate predictor of job success, and a candidate’s agreeableness, often mistaken for a sign of potential, is not the full picture.
First, let’s examine what the term agreeableness is in terms of an interview and how this can influence the hiring team’s ability to evaluate the candidate’s job skills. In psychological terms, agreeableness is one of the Big Five personality traits and reflects qualities like cooperativeness, kindness, trust, modesty, and a desire to avoid conflict. In interviews, agreeable candidates often come across as:
Warm and friendly
Respectful and deferential
Eager to connect and please
Optimistic and collaborative
Candidates can intentionally or unconsciously display agreeableness by:
Smiling frequently and maintaining eye contact
Agreeing with interviewers’ comments and appearing non-confrontational
Using inclusive and enthusiastic language
Expressing a strong desire to “be part of the team”
While this often leads to positive impressions, it may overshadow important deficits in skills, critical thinking, or reliability. While these traits can be valuable in many team-oriented roles, they do not necessarily reflect a candidate’s ability to perform the job or drive results under pressure. Interviews, especially unstructured ones, are vulnerable to cognitive biases that skew evaluations. Two of the most common are:
Halo Effect: A positive impression in one area (e.g., likability or appearance) “glows” into unrelated areas (e.g., perceived competence or work ethic).
Horn Effect: A negative trait (e.g., appearing nervous) unfairly drags down perception in other areas (e.g., leadership potential).
When a candidate is highly agreeable, the halo effect often kicks in—interviewers assume they are also organized, intelligent, motivated, and trustworthy, even without clear evidence.
Agreeableness vs. Conscientiousness: A Critical Distinction
Conscientiousness—the most consistently validated predictor of job success—refers to traits such as:
Reliability and dependability
Strong sense of duty
Goal orientation
Organizational skills
Attention to detail
In interviews, a conscientious candidate may:
Provide structured, specific answers with examples
Demonstrate preparation and clarity about responsibilities
Show accountability in discussing past work
Exhibit long-term planning and commitment to improvement
By contrast, an agreeable candidate may:
Be socially smooth but vague
Over-emphasize enthusiasm without detail
Avoid discussing challenges or failures
Prioritize making a good impression over being precise
What the Research Says
Unstructured interviews—casual, free-form conversations—have low predictive validity, with a correlation of around 0.20 with actual job performance (Schmidt & Hunter, 1998). That’s only slightly better than chance.
By contrast, structured interviews, where every candidate is asked the same set of competency-based questions and rated using consistent rubrics, fare much better. These offer a validity range of 0.44 to 0.63 (TestGorilla, 2023; Wikipedia, 2024), making them far more reliable.
“First impressions often have little correlation with long-term success on the job” (Wired, 2020).
Role of Personality Traits
Conscientiousness—a trait associated with diligence, reliability, and goal orientation—has been found to be the strongest Big Five personality predictor of job success, with correlations between 0.30 and 0.50 (Wilmot & Ones, 2019).
While agreeableness may contribute to Organizational Citizenship Behaviors (OCB) like helping colleagues, it is not a strong predictor of performance in most roles (Wikipedia, 2024). Traits like openness and extraversion may matter more depending on the job context.
Predictive Validity: Methods Compared
(Source: Schmidt & Hunter, 1998; Schmidt, 2016)
Best Practice: Combine Methods
The most effective hiring processes combine structured interviews, work sample tests, cognitive ability tests, and personality assessments. When thoughtfully integrated, these tools provide a composite predictive validity of 0.65–0.70—a dramatic improvement over any single method.
For example:
Structured Interview (0.44) + Cognitive Test (0.51)
= Composite Validity ~0.65–0.70 (assuming methods are uncorrelated)
At Allegiant Professional Resources, we help companies shift from intuition-based hiring to evidence-based talent acquisition strategies that deliver real results.
Schmidt, F. L., & Hunter, J. E. (1998). The validity and utility of selection methods in personnel psychology: Practical and theoretical implications of 85 years of research findings. Psychological Bulletin, 124(2), 262–274. https://doi.org/10.1037/0033-2909.124.2.262
Schmidt, F. L. (2016). The Validity and Utility of Selection Methods in Personnel Psychology: Practical and Theoretical Implications of 100 Years of Research Findings. University of Iowa.
Wilmot, M. P., & Ones, D. S. (2019). Occupational characteristics moderate personality–job performance relationships: A meta-analytic investigation. Journal of Applied Psychology, 104(3), 432–459.
Wikipedia contributors. (2024). Personnel selection. Wikipedia. https://en.wikipedia.org/wiki/Personnel_selection
TestGorilla. (2023). Why structured interviews outperform unstructured ones. https://www.testgorilla.com/blog/structured-vs-unstructured-interviews
Wired. (2020). Forget job interviews: Why first impressions count for nothing. https://www.wired.com/story/forget-job-interviews-first-impressions-meaningless
