Male mammals compete for reproductive access to females. Gaining and maintaining this access can be stressful and anxiety-provoking. In humans, anxiety and associated protective behaviors can manifest as jealousy. Physiological stress is likely to increase in relation to jealousy as it does with anxiety. Hypothetically, higher levels of anxiety and cortisol may indicate, and may even promote, strong territorial or jealous behavior. Chronically elevated cortisol has been shown to be deleterious to prefrontal and hippocampal neurons and result in emotional and stress-response dysregulation. In very anxious and jealous individuals, chronic stress activation could further promote these tendencies via emotional disinhibition. Cortisol production also related to vasopressin (AVP) levels and AVP has been shown to increase mate preference and territoriality. Furthermore, physiological measures may be more valid than self-report of less socially desirable behaviors such as jealousy and anxiety. As a preliminary study, we measured salivary cortisol, heart-rate, and blood pressure in relation to self-reported anxiety and jealousy in healthy men and women in response to threatening male faces paired with smiling female faces. Elevated anxiety positively predicted jealousy in men but not women. Anxiety and jealousy also predicted elevated heart rate and blood pressure. Cortisol levels in response to the threat task and in relation to jealousy approached statistical significance (ps \u3c 0.07) and suggest the need for a larger sample size