Meet the team

Impactive Associates was established to help investment firms, no matter what size, make their transition to responsible investment more straightforward and rewarding. As practitioners, our aim is to equip our clients with the knowledge and tools they need for responsible investment to flourish organically at their firms. In order to do so effectively, we take the time to fully understand their business, challenges, culture and strategy.

Mais Callan

Founding Director

Mais has over 15 years' experience in responsible investment. She led the ESG integration and research programme at one of the UK's leading asset management firms, Hermes Investment Management. She has advised some of the world's most prominent pension funds on stewardship, and represented them in board-level engagements with listed corporations in Europe and Emerging Markets. She also worked with policy makers to develop and promote best practice in sustainability and responsible investment.  Mais’ expertise also includes integrated reporting and developing quantitative and qualitative ESG research tools.


Mais holds a Masters in Diplomatic Studies from the University of Westminster and a BA (Hons) in Economics, International Business and French from the University of Surrey. She is fluent in French, Spanish and Arabic. She is a Committee member of the Institute of Directors' Young Director's Forum (IoD YDF) and a member of Women in Business and Finance.

Paul Lee

Senior Advisor

Paul is an independent consultant on ESG and stewardship. Among current projects are advising a major UK asset owner on its approach to ESG, and working with the CIO of a leading fund manager on ensuring the firm's policies are delivered in practice by his investment teams. He has delivered detailed ESG analyses and proposals for enhancement for both an Indian and an Australian company, and has developed stewardship best practice and training materials for the ICGN, CFA UK and the Investor Forum. He was previously Head of Corporate Governance at Aberdeen Asset Management, and prior to that Head of Investment Affairs at the UK's National Association of Pension Funds (NAPF). Paul worked for more than a dozen years at Hermes Fund Managers, including helping to create and build its Equity Ownership Services unit.


Paul has also held a number of non-executive roles, including being a member of the Auditing Practices Board (and then the Audit & Assurance Council of the FRC), a director of Hermes EOS's Australian joint venture Regnan, an NED at the Quoted Companies Alliance, an advisory board member at South Africa's Frater Asset Management (now Element Investment Management), and a public member of Network Rail. Furthermore, he was a member of the Enhanced Disclosure Task Force (fostered by the Financial Stability Board) and remains a member of the Capital Markets Advisory Committee of the International Accounting Standards Board -- the main investor body inputting on the development of IFRS standards.

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