In Harvard Business Review in March 2026, executive coach Jenny Fernandez opens a piece called "When Senior Leaders Lack People Skills, Transformations Fail" with a short, unsettling case. A new chief transformation officer at a growth-stage biotech, six weeks into the role, watches the dashboard tilt the wrong way. Engagement scores have dropped 40%. Turnover has doubled. The senior team, technically brilliant, are presenting restructuring plans into rooms that look aligned and feel silent. The teams underneath are not aligned. They are leaving.
The diagnosis Fernandez offers is not flattering and not new. Senior leaders read a room they cannot read, and the people in it stop telling them. Six weeks is long enough for the damage to register on a measure as inert as engagement. It is not long enough for the story to reach the leaders making the decisions.
Why It Is A Behaviour Number, Not An Awareness Number
The HBR piece is one report among many converging on the same point. McKinsey's transformation research, repeated across two decades and tens of thousands of programmes, finds that around 70% of large change efforts miss their stated goals. The figure is so familiar that it has lost most of its sting. What it actually means, when set next to the Fernandez case, is that the median large transformation produces a six-week drop somewhere, the senior layer either misses it or sees it too late, and the programme never recovers the trust it had on day one.
Deloitte's 2026 Global Human Capital Trends study points to the same gap on the other side of the leader. Sixty-six percent of C-suites say their organisation's traditional functions must change to keep pace, and only seven percent say they are making significant progress. The strategy decks are not the bottleneck. The behaviour of the people running the room is.
The reason senior leaders miss it is rarely arrogance. It is the same Dunning-Kruger pattern that turns up in every dataset that compares self-rated communication ability with observed behaviour. Confident self-report, mediocre observed performance. People stop telling a leader things, the leader notices the absence of dissent, and the brain reads that as alignment. By six weeks in, the gap between what the leader thinks is happening and what is actually happening is large enough to read in a quarterly engagement pulse.
What Most Organisations Try
The default response when a transformation begins to wobble is more communication. A town hall, a refreshed deck, an FAQ. Sometimes a 360-degree feedback round for the senior team, with anonymous comments tagged to behaviours like "listens", "challenges constructively", "follows through". The feedback is shared, often skimmed. Two months later, the same conversation in the same room produces the same silence.
The mechanism is well established. Roediger and Karpicke, in Psychological Science (2006), showed that being tested on material lifts long-term retention by roughly 50% compared with re-reading. Most senior-leadership development is the re-reading kind. Read the 360, read the framework, read the case study, return to work. By the time a real meeting happens with a real, hesitant direct report, almost none of what was read is accessible under time pressure. The leader defaults to the instinct they had on day one.
Anders Ericsson's Peak (2016) is even more direct on this. The first-reaction behaviours that determine whether a transformation conversation lands, asking before telling, naming a concern that nobody else will name, holding silence long enough for the room to fill it, change only with deliberate, feedback-rich practice against a clear behavioural target. They do not change with insight.
What Actually Works
In Sidestream's own academic behaviour-change work, building on research from UCL, Cambridge and Bocconi, participants who learned a communication skill through immersive role-play scored roughly 20% higher on observed behaviour than participants who learned the same content through video or slide-show training. Self-rated confidence did not predict observed performance. We design the self-report out by measuring the behaviour, not the certainty.
Applied to the senior layer, the pattern is small group, professional actor playing a stretched director or sceptical board member, three or four full conversations, replayed with feedback against named behavioural anchors. By the third rehearsal the right move (ask the second question, hold the silence, name the thing nobody is naming) is the first one rather than the rescued one. Six weeks in, the engagement pulse looks different because the rooms looked different in week one.
What We Do About It
Our immersive simulations and senior-leader workshops are designed for exactly the rooms that derail transformations: the ones where the silence is read as agreement and a 40% drop is loading underneath. The format is short, intense and behaviourally measured. Read also our piece on the 70% transformation failure rate for the McKinsey pattern, or our piece on the four frictions for the leader-as-friction-source angle from HBR.
People skills are not a temperament question. They are a rehearsal question, and the rehearsal happens before the transformation, not after.
The transformations that hold their numbers past week six are not the ones with the cleverest strategy. They are the ones where the senior team has rehearsed the awkward conversation often enough that the default move is the right one. Book a call to look at what that rehearsal would look like for your top team.
Book a free 30-minute diagnostic call → or read about our research-backed approach.