# John Kearon

> John Kearon is a British entrepreneur, market researcher and author who founded BrainJuicer in 2000, later renamed System1 Group. A former Unilever marketer and advertising planner, he built a research business around emotional responses and behavioural science, led it onto AIM in 2006 and co-authored System1: Unlocking Profitable Growth. He handed the CEO role to James Gregory in 2022 and exchanged his System1 shareholding for Brave Bison shares in March 2026.

- **Role:** Founder and former CEO of System1 Group; shareholder in Brave Bison
- **Organizations:** System1 Group PLC (formerly BrainJuicer), Brave Bison Group plc, Brand Genetics, Unilever, Publicis/FCA, ESOMAR Foundation
- **Nationality:** British
- **Education:** LLB, Law and Politics, University of Birmingham
- **Known for:** Founded the business that became System1 Group and led BrainJuicer to an AIM listing in 2006., EY Emerging Entrepreneur of the Year, 2005., EY London regional Entrepreneur of the Year, 2009.

## Career timeline

- **1986** — Began his career at Unilever, later holding research and marketing positions.
- **1990s** — Worked as planning director at Publicis/FCA and founded innovation agency Brand Genetics.
- **1999–2000** — The principal operating company was incorporated on 29 December 1999; Kearon dates BrainJuicer’s launch to January 2000.
- **2003** — Unilever Ventures backed BrainJuicer.
- **2005** — Opened offices in the Netherlands and New York.
- **2006** — BrainJuicer floated on the London Stock Exchange’s AIM market.
- **2017** — BrainJuicer became System1 on 1 April. Co-authored System1: Unlocking Profitable Growth with Orlando Wood and Tom Ewing and became ESOMAR Foundation president.
- **2022** — James Gregory succeeded him as CEO on 1 December.
- **2023–2025** — Worked on US expansion and led invention through System1 Futures.
- **2025** — Moved to a non-executive role from 1 September and headed strategic and product advisory committee QualCo.
- **2026** — Exchanged his approximately 23% System1 stake for Brave Bison shares in March and left System1’s board. Karin Lieshout succeeded him as ESOMAR Foundation president, announced in July.

## Achievements

- Founded the business that became System1 Group and led BrainJuicer to an AIM listing in 2006.
- EY Emerging Entrepreneur of the Year, 2005.
- EY London regional Entrepreneur of the Year, 2009.
- Advertising Research Foundation Gold Award for Great Mind/Research Innovator, 2008.
- BrainJuicer won ESOMAR Best Methodology awards in 2005 and 2007.
- Co-authored System1: Unlocking Profitable Growth with Orlando Wood and Tom Ewing, published in 2017.
- Led ESOMAR Foundation as president from 2017 until the succession announced in July 2026.

## Latest updates

- **2026-10** — System1’s 15 October response to Brave Bison’s offer reiterated that Kearon no longer had operational or executive involvement; the board recommended rejecting the offer.
- **2026-07** — Brave Bison’s investor register, updated 14 July, listed Kearon with 9,763,821 shares, an 8.4% holding.
- **2026-07** — The ESOMAR Foundation announced Karin Lieshout as president, succeeding Kearon, who had held the role since 2017.
- **2026-03** — Exchanged his roughly 23% System1 shareholding for Brave Bison shares and departed the System1 board.

## Links

- Website: https://system1group.com/
- LinkedIn: https://www.linkedin.com/in/john-kearon-system1/
- Twitter/X: https://twitter.com/ChiefJuicer

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Profile page: https://yespress.io/john-kearon
Published by YesPress — https://yespress.io
Last updated: 2026-10-22