There are few recruiting practices in business as familiar as the job description, and one of its most basic and entrenched components is the list of candidate qualifications and skills. For instance, a recent job listing for a sales executive position on Monster.com said that applicants must have “a bachelor’s degree, a minimum of at least two years selling in healthcare IT or a related field, excellent communication skills, and be a team player with a positive attitude.”

This list of qualifications seems like common sense. And yet, this common sense approach to recruiting may be the single biggest obstacle to hiring the best person for a job. Why? Because such job descriptions are rooted in a flawed and obsolete way of thinking about employees. That is, they look at candidates as averages instead of individuals.

This misguided mindset originated in Europe in the 19th century with the invention of the “Average Man” by a Belgian mathematician, which led the first generation of social scientists to develop the practice of “typing” in which they averaged the qualities of each class of people to describe the essential traits of the “soldier type,” “criminal type,” or “ironworker type.”

For the past century, the same kind of thinking has led to job descriptions that identify the presumed essential qualities of a type of employee, such as a typical sales executive. There is a huge hidden problem with typing, however: it steers attention away from what is relevant and informative about an individual candidate.

Fortunately, there is a better approach to recruiting, one grounded in a new interdisciplinary science known as the Science of the Individual. This science rejects the entire notion of the “Average Man” and relies on the math of 21st century dynamic systems theory rather than 19th century statistics.

One of the key concepts of the science of the individual is the context principle, which holds that performance always depends on the interaction of a specific individual and a specific situation; it is meaningless to evaluate an individual’s ability or potential without referring to the environment in which the individual will be performing.

The context principle has already transformed many of the fields that once relied on typing. Oncologists have switched their emphasis from standardized treatments for standard types of cancer to personalized treatments that target the specific physiological contexts of individual cancer. And biologists no longer study models of “standard cells” but the dynamic activity of “individual cells in context.”

But the context principle holds the potential for the greatest impact in business hiring.

Instead of describing the type of employee you think you want to hire, the context principle suggests it is better to focus on the particular performance a job demands and the particular contexts where the employee will be performing, and then look for candidates who have successfully executed similar performances in similar contexts.

Consider the sale executive job description above. That job requires that candidates possess a Bachelor’s degree, probably because the typical sales executive possesses a bachelor’s degree. Next, the job description demands a minimum of two years of experience. Again, this is presumably the average amount of experience that similar sales executives possess. And finally, insisting upon “excellent communication skills” might seem like a no-brainer, but once again this is an average-based summary rather than something precise and explanatory.

None of these requirements provide insight into the actual constellation of a candidate’s abilities, and more importantly, fulfilling them provides almost no useful information about whether the candidate can execute the specific performance we need in the specific job contexts.

So what can replace the job description’s venerable list of qualifications and skills? One man who has pioneered a practical and effective context-focused method of recruiting is Lou Adler, founder of the Lou Adler Group. He developed a new way to recruit and hire employees that he calls “performance-based hiring.” Adler explains: “Instead of describing the person they want, employers describe the job they want done.”

Before switching to a career in recruiting, Adler designed parts for an aerospace manufacturer. This might be why he approaches the practice of selecting employees with the mindset of an engineer who knows that selecting the right material for a part depends on accurate knowledge of the environment where the part will be used.

Adler gives one example where performance-based hiring produced better results than the generic job description. A social media startup in Britain needed to hire someone to head their marketing team. They put out a listing of the qualifications and skills of a typical marketing director and ended up hiring someone with many years of marketing experience and an impressive resume. Yet he turned out to be a complete disaster. Why? All of his experience was at large corporations with sizable budgets and hierarchical management. The startup, however, was much more dynamic and fast-paced, with a smaller marketing budget and a more informal approach to management. The new context was different from the ones where the marketing director had been successful, and as a result he was a terrible fit.

The start-up turned to Adler, who used performance-based hiring to help them identify a very counter-intuitive prospect, a pharmacist without any marketing experience. Though the CEO was skeptical at first, Adler showed how the pharmacist had actually performed the same kinds of tasks that the startup’s marketing director would need to do, in similarly dynamic, fast-paced, low-budget, informal settings. The pharmacist turned out to be a huge success and is now one of the company’s most effective and influential employees.

There is another benefit of context-aware hiring: it makes employees feel more connected and fulfilled by their jobs, which makes them more productive and loyal. It also makes it easier to recruit great candidates.

The Adler Group has helped more than 10,000 hiring managers adopt performance-based hiring at businesses ranging from shoestring startups to Fortune 500 companies. “Companies always lament there’s a shortage of talent, that there’s a skills gap. But really there’s just a thinking gap,” Adler says. “If you spend the effort thinking through the contextual details of the job, you’re going to be rewarded.”

Todd Rose and Ogi Ogas are the authors of The End of Average: How We Succeed in a World That Values Sameness (HarperOne, 2016).