We give the honest read, not the comfortable one. Fast feedback, real talk, no dressing up what isn't working. This is a standard, not a style.
Tenax Propositi. Tenacious of purpose.
The Gibbs family motto since 1691. We contracted it into our name — Tenaxiti — because it is exactly what we do: help leadership teams turn complex strategy into execution that holds, and stay until it does.
The difference
Psychologists who have run companies.
Your hardest problems don't sit in one box. The strategy is sound but it won't execute. The team is capable but not aligned. Every decision still routes back through you. That's people and business at once — and most firms do only one, so you either choose, or hire two and manage the seams.
We're both organisational psychologists who have also run companies — as CEO and as managing director. So the people reading your team's dynamics have also sat where you sit and answered for the results. Nothing is handed off to specialists or down to juniors: Tenaxiti is the two of us. Some engagements we run together, some one of us leads, but both minds are on every piece of work.
Both partners are practising board directors.50+
Executive teams
25+
Years combined executive leadership (GM+)
20+
Years organisational psychology
We haven't just advised people in those seats. We've occupied them.
Who you'll work with
We've run organisations. We understand the people in them.
Neither of us came to this from theory. We came from practice — executive practice, at scale, under real pressure. We've occupied the seats, run the companies, and made the calls ourselves.
What leaders say about their experiences and benchmarks.
What surprised us most was how the process brought our leadership team together in a way we hadn't experienced before. Anthony and Shannon were exceptional — the way they challenged us to move beyond our standard thinking into genuine future-focused growth was something special to witness.
Michael ArgyrouGroup CEO, Hickory
On one defence-sector leadership team, trust climbed from the team's weakest dimension to higher than 84% of teams worldwide — with accountability finishing at the 89th percentile globally. Measured at re-assessment, eighteen months on.
I engaged Shannon to help with teamwork and interpersonal dynamics within my teams. She built trust and rapport with the group very quickly, and has positively impacted teamwork and team performance.
Glenn AndersonExecutive Manager Operations, DBCT
Anthony has a rare ability to engage and hold the team's attention — explaining why we do what we do, in a clear and rational way, backed by a deep knowledge of the science. His insights have helped us make tangible progress.
Jeffrey WhitemanCEO, Mastermyne
How we work
We work the behaviour and the structure. At the same time.
The read
Psychology trained us to see what's actually happening beneath the behaviour. Not a guess or a hypothesis — a structured read of the system, run before any intervention is designed. The constraint is almost never where it first appears.
The work
We work people and business together. How leaders think, decide and operate under pressure — and the strategy, decision rights and operating rhythm that let the team execute without every call routing through the CEO. Designed with the team that has to live with it. A plan on a page. An operating rhythm that runs.
The standard
Tenax Propositi — tenacious of purpose. It is our name, and it is the standard we hold the work to. Measured against the diagnostic baseline, evidenced by the team. Then we step out.
Teams aren't dysfunctional. They're polite. Strategies aren't wrong. They're stranded. The constraint lives in the system underneath.
Core values
Five lines we hold.
Not values on a wall — lines we've come to hold, because we've seen the alternative. They decide who we work with, what we take on, and when we walk away.
Our story
Three centuries of practice. One standard.
A family motto came first, in 1691: Tenax Propositi. Three centuries later, two psychologists — trained and working apart — arrived at the same firm on the same day, took two paths to the top, and built one practice around the standard it set. They named it for the motto: Tenaxiti.
- 1691
Tenax Propositi.
Tenacious of purpose. The Gibbs family motto, carried down three centuries. Inherited, not branded.
- 2008
Both careers begin.
Two psychologists, from two branches of the field — Shannon organisational, Anthony clinical. Both join Sentis on the same day in June.
- 2016
Anthony, CEO of Sentis.
Nine years leading a global organisational-psychology firm across 22 countries, after four as Chief Operating Officer — and, on his watch, named one of Australia's Best Workplaces. Thirteen years in the C-suite.
- 2020
Shannon, MD at Hudson.
Managing Director of the talent practice across Australia and New Zealand. She had already led commercial turnarounds and, at the height of COVID, rebuilt a national service line entirely online.
- 2023
Shannon founds Tenaxiti.
The motto becomes the name: Tenax Propositi, contracted to Tenaxiti. Psychology and executive practice, brought together.
- 2025
Tenaxiti grows.
After seventeen years at Sentis, Anthony leaves to join Shannon. We hold firm through the complexity and stay until the change holds — exactly what the name has meant since 1691.
- 2026
Just getting started.
Varsana Verbruggen joins to run the operating rhythm, keeping both partners in the work itself. More executive teams, deeper work, an open future.