Corinna Peifer is a psychologist at the University of Duisburg-Essen specializing in the physiological correlates of psychological states, with flow as her primary focus. Her most distinctive empirical contribution is establishing that flow is not a state of physiological calm but of moderate arousal: the relationship between cortisol levels and flow follows an inverted-U pattern, with too little or too much cortisol both undermining the flow state.
Cortisol and the moderate arousal finding
The common popular account of flow — that it is a state of effortless, stress-free immersion — is physiologically incomplete. Peifer's research using salivary cortisol as a stress marker found that flow is associated with moderate cortisol activation, not baseline or suppressed cortisol. This finding is conceptually important: the flow state requires a level of physiological mobilization sufficient to sustain focused engagement, but not so elevated as to trigger the anxious hypervigilance that breaks absorption.
This connects flow physiology to the challenge-skill-balance model in a non-obvious way. The perceived challenges that produce flow are genuinely stimulating — they generate real physiological arousal — but they are matched to skill sufficiently that the arousal stays within a productive range. Very low challenge produces boredom with correspondingly low arousal; very high challenge produces anxiety with high cortisol and the hyperactivation that breaks the merging of action and awareness.
Peifer's cortisol findings are empirically grounded in controlled studies using within-subjects designs, where participants engage in tasks calibrated to different challenge levels. The moderate arousal requirement is one of the few physiological claims in flow research with reasonably consistent replication, unlike some of the flow-neurochemistry claims in popular literature that rest on limited neuroimaging evidence.
Flow and burnout
Peifer has also investigated the relationship between flow and occupational burnout. The relationship is bidirectional and more complex than it initially appears. Regular flow experiences appear to be protective against burnout — the positive affect, sense of competence, and intrinsic motivation that flow generates counteract the emotional exhaustion and cynicism that characterize burnout. However, flow in certain occupational contexts can also be a risk factor: highly engaging work can extend working hours, reduce recovery time, and mask early burnout signals. Workers who regularly experience flow may work longer and harder than is sustainable because the activity itself provides no phenomenological warning of approaching depletion.
bakker's work on the Job Demands-Resources model provides the structural context for this paradox: flow in high-resource environments (autonomy, support, feedback) is genuinely protective, but flow in high-demand environments (even when flow occurs) can be a pathway to burnout if the demands continuously exceed recovery capacity. Peifer's physiological research adds specificity to this: the cortisol activation that enables flow is manageable in moderate amounts, but if arousal is chronically elevated — even when subjectively experienced as flow — it produces the allostatic load associated with burnout.
Advances in Flow Research, second edition
Peifer's co-editorship with engeser of the 2021 second edition of advances-in-flow-research reflects her standing as a synthesizer of the field's empirical literature. Her editorial contribution was particularly significant for integrating physiological research — which had been progressing largely independently of psychological and organizational flow research — with the broader academic literature. The 2021 edition is more interdisciplinary than the 2012 original, and the integration of neuroscience and physiology is primarily Peifer's contribution.
Position in the lineage
Peifer addresses one of the most important gaps in the flow research tradition: the lack of objective physiological markers to complement self-report measures. Her cortisol work gives flow research a physiological anchor that goes beyond dietrich's theoretical transient hypofrontality model, providing empirical measurement of arousal states rather than inference from neurological theory. For the KB's goal of distinguishing empirical findings from theoretical claims, Peifer's work represents the empirical side of flow physiology — carefully measured, conservatively interpreted, with clear acknowledgment of what remains uncertain.