This past week, the EEOC joined a probe behind a federal class action lawsuit against Google filed last month, charging that the search giant “engaged in a systematic pattern” of discrimination against applicants over the age of 40. The suit, expanding upon a related case filed earlier this year, cited data from Payscale that placed the median age of Google’s (GOOGL) workforce at 29, with a margin of error of 4%. By contrast, the median age for U.S. computer programmers is 43.

This mindset is echoed by word and deed around Silicon Valley. At a 2011 Bangalore tech conference, venture capitalist Vinod Khosla warned, “People under 35 are the people who make change happen. People over 45 basically die in terms of new ideas.”

If the accusations against Google are true, the company has clearly offered exemptions to its 40-something founders Larry Page and Sergey Brin and its 64-year-old executive chairman Eric Schmidt.

While Silicon Valley seems to have cast off the over-40 set, we have some of the oldest national political leaders in history. The average age in the U.S. Congress is 57 in the House and 61 in the Senate, with several octogenarian elected officials, including Diane Feinstein and John Conyers. The Supreme Court has vital octogenarians like Ruth Bader Ginsburg and Anthony Kennedy, with Stephen Breyer soon to join the club. Hillary Clinton would be 69 if she takes office in January, Donald Trump is 70, and Bernie Sanders will turn 75 in September. No one would deny that Trump and Sanders are disruptors.

This month, 77-year-old Mavis Staples and 75-year-old Bob Dylan performed 30 rousing songs before a packed house of thousands that spanned several generations at the Tanglewood Music Center in Lenox, Mass. Paul McCartney, at 74, also mesmerizes crowds with representatives of many different age groups. Last April, for a Robin Hood Foundation event, he filled New York’s enormous Javits Center with an even mix of Baby Boomers, Millennials, and Gen Xers with an energetic rendering of 35 songs back-to-back with breaks only to replace the guitars he wore out.

People’s opinions about the abilities of the aging and the elderly tend to evolve as they themselves grow older. When he was 48, the acerbic New York Times columnist William Safire condemned the 1980 Age Employment Discrimination Act that protected people from mandatory retirement at 65. He lamented: “Old people get older and usually less productive and they ought to retire so that business can be better managed and society more economically served. We should treat the elderly with respect, which does not require treating them as if they were not old.”

Safire continued to write his twice-weekly column for the Times almost until his death. He worked for roughly another 30 years beyond his 1980 commentary about aging. And former United Auto Workers boss Douglas Fraser confided to me in 1985 that he regretted coauthoring, as an ambitious rising union leader, the policy forcing out union bosses at 65.

Research by Northwestern University economist Benjamin Jones indicates that Nobel laureates since 1985 created their prize-winning work at an average age of 45, the same age at which most inventors had their great achievements. Copernicus offered his general theory of the universe at age 70. Virtually no physicist or chemist has won the Noble prize for work done in their 30s or earlier in their lives.

Alfred Hitchcock directed his masterpiece Vertigo when he was 59; Frank Lloyd Wright built Fallingwater when he was 68. And Benjamin Franklin co-authored the Declaration of Independence at 70.

The great pianist Claudio Arrau commented in his 80s, “Age is biological, but psychologically when I am playing I feel like a young man. My muscles have acquired a wisdom of their own and I think they are working better than ever.”

Northwestern’s Jones found that while some IT breakthroughs have come from a few young people, this has not been case for life sciences, chemical engineering, nanotechnology, or clean energy. Commenting on this in The Washington Post, Stanford’s Vivek Wadhwa quipped, “It may well be the only people who are really set in their ways and ‘keep falling back on old habits’ are Vinod Khosla and the old-time VCs. The rest of us aren’t too old to take risks or innovate.”

Older workers have greater sales skills, interpersonal savvy, and only modest declines in physical dexterity. Research on age and risk in engineering found that older managers in this particular field were only somewhat less willing to take risks. Older managers took longer to make decisions, but they were better able to appreciate the value of new information.

Youth is no guarantee of brilliance and age does not ensure wisdom – nor dementia. I’ve seen many students and clients burn out in their 30s and septuagenarians champing at the bit for adventure. Sure, Viacom’s (VIAB) 93-year-old Sumner Redstone is not at the top of his game, but his much younger successor Philippe Dauman has been failing in office for over a decade.

Such entrepreneurs as Sam Walton of Walmart, Bill McGowan of MCI, and McDonald’s Ray Kroc, among many others, did not launch their maverick businesses until after their fifth and sixth decades. Henry Ford did not introduce the Model T until after he was 45. Alibaba’s Jack Ma is 51. Zhang Ruimin, the CEO of China’s Haier, led his company to global dominance at age 67. And Steve Jobs’ most successful innovations, including the iMac, iTunes, iPod, iPhone, and iPad, were developed after age 45.

At our most recent Yale CEO Summit, where our theme was “disruption,” we did not celebrate Silicon Valley wunderkinds but rather a set of inspiring septuagenarians and octogenarians, such as venture capitalist Alan Patricof, former NBA chief David Stern, former American Express CEO James Robinson, and former SEC chairman Bill Donaldson—all of whom are still active champions of new enterprises. Our chief frustration is that we missed our chance to honor 60 Minutes’ Morley Safer, who recently died at 84 but continued to produce brilliant journalism until a week before his death.

Finally, this past week, Elie Wiesel died at 87, having never retired from his campaign for social justice and human rights. Perhaps it is better to never “act your age.”

Jeffrey Sonnenfeld is a senior associate dean and professor at the Yale School of Management as well as the author of The Hero’s Farewell (Oxford University Press). He is also a past board member of the AARP and the National Council on Aging.

Editor’s note: A previous version of this story incorrectly referred to former NBA Commissioner David Stern as a former NBC chief.