"Silicon Valley has become one of the most ageist places in America," contended journalist Noam Scheiber in New Republic last year. He's not the only one who's noticed the industry's preference for young employees, nor is Silicon Valley the only place where ageism lurks.

But if you're among those entrepreneurs who secretly wonder if younger employees aren't both more innovative and more willing to give your business their all, then a new study should be required reading for you. According to the findings, what matters when it comes to finding excellent employees isn't chronological age, it's the age of the spirit.

The advantages of being young at heart

The study, led by German professor Florian Kunze, surveyed 15,000 employees from 107 companies to find out what matters more in hiring: actual youth or being young at heart. What did the researchers find? The British Psychological Society's Research Digest blog sums up the results:

"Employees who felt substantially younger than their chronological age were more successful in meeting the goals they'd promised their managers they would achieve. Companies with more of these 'young at heart' employees also tended to perform better overall, in terms of financial performance, efficiency, and a longer tenured work force."

As the BPS notes, the study offers an intriguing suggestion that having folks on staff who feel younger than they are can have big business benefits, but, given the way the research was designed, it can't prove causality--is it being in certain vibrant companies that makes employees feel young or does having young-at-heart employees make a company vibrant? But whichever way the arrow of causation points, the results indicate that building a culture that makes those who are younger than their years feel at home can pay big dividends, and that means tackling any hint of age discrimination in your organization.

"The survey also showed that organisations tended to have more young at heart workers when they offered both age-inclusive policies, and, on average, their employees felt that their work was more important and meaningful," reports the BPS, adding that "climates where all workers can feel young, energised by their work, and not judged and stereotyped, facilitate the kind of dynamic performance associated with [the young]."

So if you're subtly throwing off signs that those with a few wrinkles or grey hairs might not feel as at home at your business, know that you're probably doing your company a double disservice, both driving away older high performers and probably creating a climate that prevents anyone a bit older on your team from reaching their full potential. Better to encourage all employees--no matter their birthdate--to stay hungry and creative, and to convey that you believe those capabilities have nothing to do with calendar age.