The Field Guide › Paper
A longitudinal study using multilevel growth modelling on data from over 10,000 healthcare workers, tracking how psychological safety actually changes over an individual's time on a team rather than assuming it simply builds with tenure and familiarity, as most cross-sectional psychological safety research implicitly does. The central finding, the 'Paradise Lost' effect the title refers to: newcomers with less than a year of tenure report higher psychological safety than their more-tenured colleagues, and this advantage erodes as tenure accrues rather than continuing to build. The proposed explanation runs through socialisation: new arrivals are initially given a kind of grace period, seen as still learning and not yet expected to know the ropes, which makes admitting uncertainty or raising concerns feel lower-stakes; as tenure accrues, that latitude narrows, people are increasingly judged against established norms and assumed competence, and interpersonal risk starts to feel more consequential. A strong departmental-level psychological safety climate dampens this downward trajectory for newcomers, meaning the erosion isn't inevitable and can be buffered by the surrounding team and organisational context. A further, genuinely important multilevel finding: as tenure increases, an increasing share of the variance in an individual's psychological safety is explained by person-level factors rather than group-level climate, meaning psychological safety becomes progressively more individualised and less climate-driven the longer someone has been on a team, which complicates any simple 'just fix the team climate and everyone benefits equally' assumption. Proposes an integrated multilevel framework connecting individual-level and group-level factors to explain both the emergence and the ongoing fluctuation of psychological safety over time, arguing it shouldn't be treated as a stable team-level trait that simply increases with familiarity, but as something dynamically co-produced by situated interactions between individual dispositions and experiences on one hand and group climate on the other, capable of falling as readily as it rises depending on what happens along the way.