Objective: To examine the association of social desirability (SD) responding (“defensiveness”) and cortisol levels. Methods: Marlowe–Crowne SD scores and morning salivary cortisol were measured in firefighters. Results: SD scores were associated with higher cortisol levels ( r=.28) in 60 firefighters under age 45, but not in 25 older firefighters (or the combined sample). Conclusion: The results are consistent not only with SD scores being an indicator of coarctation of experience as a coping mechanism, but also (at least for younger persons) perhaps a risk factor for the psychobiological dysfunctions associated with chronic elevations of cortisol.