From buffering to binding: how social support reconfigures career sustainability trajectories under work–family conflict

Purpose Prior work–family research reports unstable longitudinal effects of conflict and support yet lacks a theory that treats time as theoretically active. This study addresses that gap by conceptualising work–family conflict and social support as phase-dependent resource processes that reconfigure career sustainability trajectories rather than exerting stable, monotonic effects. Design/methodology/approach A three-wave longitudinal panel of 421 full-time employees was analysed using latent growth curve modelling. Higher-order constructs of work–family conflict, social support resources, and career sustainability were specified to separate intercept displacement from slope dynamics and to test moderated growth and sequential mediation over a twelve-month window. Findings Work–family conflict depressed baseline career sustainability and intensified early decline, but its total effect showed a documented pattern of attenuation across discrete measurement waves declining from β = −0.447 (T1, p < 0.001) to β = −0.309 (T2, p < 0.01) to β = −0.081 (T3, p = 0.214, non-significant) a directly observed wave-by-wave pattern consistent with progressive adaptation rather than a structurally identified non-monotonic trajectory. Social support buffered initial depletion yet flattened subsequent recovery slopes, operating through adaptive reallocation rather than sustained protection. Family-supportive supervisor behaviour altered trajectory form, differentiating early stabilisation from prolonged recovery. Originality/value The study advances the field by providing evidence consistent with the view that buffering is temporally conditional, offering findings consistent with the attenuation and directional shift of conflict effects as a theoretically expected feature of prolonged resource depletion, and suggesting that career sustainability depends on trajectory management rather than static resource accumulation.