1. Marriage and fatherhood associated with lower testosterone in males Gray, P. B., Kahlenberg, S. M., Barrett, E. S., Lipson, S. F. & Ellison, P. T. (2002). Marriage and fatherhood are associated with lower testosterone in males. Evolution and Human Behavior, 23, 193 – 201. Carlie Smith Bailey Jackson Amanda Lee Christine Requa

2. Hypotheses 1) T levels would be lower in married men than unmarried men 2) T levels would be lowest in men with children 3) Marriage duration and male spousal investment will negatively correlate with T levels among married men without children 4) Age of male’s youngest child will positively correlate with T levels 5) Measure of male spousal investment will negatively correlate with T levels Gray, P. B., Kahlenberg, S. M., Barrett, E. S., Lipson, S. F., & Ellison, P. T. (2002). Marriage and fatherhood are associated with lower testosterone in males. Evolution and Human Behavior, 23(3), 193-201. http://dx.doi.org/10.1016/S10 testosterone

3. Method & Procedure n = 58 (29 unmarried men, 14 married men without children, 15 married men with children) M = 29.6 Collected four saliva samples to measure T levels (2/morning; 2/evening) Self-report questionnaire surveying demographic, marital, and parenting backgrounds, stress inventory, spousal investment measure and male parenting effort measure. Gray, P. B., Kahlenberg, S. M., Barrett, E. S., Lipson, S. F., & Ellison, P. T. (2002). Marriage and fatherhood are associated with lower testosterone in males. Evolution and Human Behavior, 23(3), 193-201. http://dx.doi.org/10.1016/S10 testosterone

5. Results Men without children had lower evening T levels than unmarried men Greater spousal investment corresponded with lower evening T levels In the evening, but not morning male T levels consistent with predicted effects of relationship and parental status Gray, P. B., Kahlenberg, S. M., Barrett, E. S., Lipson, S. F., & Ellison, P. T. (2002). Marriage and fatherhood are associated with lower testosterone in males. Evolution and Human Behavior, 23(3), 193-201. http://dx.doi.org/10.1016/S10 testosterone

6. Results Cont...

8. Critical Review Sample only taken from Boston Future research: conduct study cross-culturally or among polygamous species to compare T levels

9. Video Clip: Fatherhood