When they were young: 40 Under 40 childhood photos

See the profile for Adam Neumann, No. 1 on the 40 Under 40.

JB Straubel, Tesla

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See the profile for J.B. Straubel, No. 2 on the 40 Under 40.

Ryan Graves, Uber

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See the profile for Ryan Graves, No. 3 on the 40 Under 40.

Logan Green, Lyft

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See the profile for Logan Green, No. 3 on the 40 Under 40.

John Zimmer, Lyft

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See the profile for John Zimmer, No. 3 on the 40 Under 40.

Dhivya Suryadevara, GM Asset Management, GM

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See the profile for Dhivya Suryadevara, No. 4 on the 40 Under 40.

James Park, Fitbit

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See the profile for James Park, No. 5 on the 40 Under 40.

Taylor Swift

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See the profile for Taylor Swift, No. 6 on the 40 Under 40.

Vas Narasimhan, Novartis Pharmaceuticals

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See the profile forVas Narasimhan, No. 7 on the 40 Under 40.

Jason Robins, DraftKings

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See the profile for Jason Robins, No. 8 on the 40 Under 40.

Jason Buechel, Whole Foods

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See the profile for Jason Buechel, No. 11 on the 40 Under 40.

Robby Mook, Hillary for America

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See the profile for Robby Mook, No. 12 on the 40 Under 40.

Noah Wintroub, J.P. Morgan Chase

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See the profile for Noah Wintroub, No. 13 on the 40 Under 40.

Hugo Barra, Xiaomi

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See the profile for Hugo Barra, No. 14 on the 40 Under 40.

Jessica Alba, The Honest Company

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See the profile for Jessica Alba, No. 15 on the 40 Under 40.

Karen Fang, Bank of America

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See the profile for Karen Fang, No. 17 on the 40 Under 40.

Anand Swaminathan, Accenture Digital

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See the profile forAnand Swaminathan, No. 18 on the 40 Under 40.

Lisa Falzone, Revel Systems

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See the profile for Lisa Falzone, No. 19 on the 40 Under 40.

Parker Conrad, Zenefits

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See the profile for Parker Conrad, No. 20 on the 40 Under 40.

Will Ackerly, Virtru

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See the profile for Will Ackerly, No. 21 on the 40 Under 40.

Orion Hindawi, Tanium

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See the profile for Orion Hindawi, No. 21 on the 40 Under 40.

Jared Kushner, Kushner Companies

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See the profile for Jared Kushner, No. 25 on the 40 Under 40.

Melanie Whelan, SoulCycle

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See the profile for Melanie Whelan, No. 26 on the 40 Under 40.

Kayvon Beykpour, Periscope

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See the profile for Kayvon Beykpour, No. 27 on the 40 Under 40.

Michelle Dipp, OvaScience

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See the profile for Michelle Dipp, No. 28 on the 40 Under 40.

Stacy Brown-Philpot, TaskRabbit

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See the profile for Stacy Brown-Philpot, No. 29 on the 40 Under 40.

Sam Altman, Y Combinator

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See the profile for Sam Altman, No. 30 on the 40 Under 40.

Chris Wanstrath, GitHub

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See the profile for Chris Wanstrath, No. 31 on the 40 Under 40.

Debbie Sterling, GoldieBlox

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See the profile for Debbie Sterling, No. 32 on the 40 Under 40.

Brian Sheth, Vista Equity Partners

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See the profile for Brian Sheth, No. 33 on the 40 Under 40.

Michael Dubin, Dollar Shave Club

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See the profile for Michael Dubin, No. 34 on the 40 Under 40.

Andy Katz-Mayfield, Harry’s

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See the profile for Andy Katz-Mayfield, No. 34 on the 40 Under 40.

Jeff Raider, Harry’s

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See the profile for Jeff Raider, No. 34 on the 40 Under 40.

Josh Goldin, Alliance Consumer Growth

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See the profile for Josh Goldin, No. 35 on the 40 Under 40.

Julian Steinberg, Alliance Consumer Growth

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See the profile for Julian Steinberg, No. 35 on the 40 Under 40.

Trevor Nelson, Alliance Consumer Growth

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See the profile for Trevor Nelson, No. 35 on the 40 Under 40.

Julia Hartz, EventBrite

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See the profile for Julia Hartz, No. 36 on the 40 Under 40.

Ashifi Gogo, Sproxil

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See the profile for Ashifi Gogo, No. 38 on the 40 Under 40.

Reshma Saujani, Women Who Code

Courtesy of Reshma Saujani
See the profile for Reshma Saujani, No. 39 on the 40 Under 40.

Ronda Rousey, UFC

Courtesy of AnnMaria DeMars
See the profile for Ronda Rousey, No. 40 on the 40 Under 40.

To see the full list of the Fortune 40 Under 40, visit fortune.com/40-under-40.

For more Fortune photography follow us on Instagram at @fortunemag.