Hormone Effects On Behavior

During the last century, clues that hormones might affect behavior arose both from laboratory experiments and in the clinic. Frank Beach, working with animals at the University of California, Berkeley, demonstrated the activation of male sexual behavior by testosterone injections, as well as the facilitation of female sexual behavior by treatments with estrogens and progesterone. In the clinic, it was clear that hyperthyroid patients could be nervous and irritable, while hypothyroid patients would be sluggish and dull. As well, eunuchs (lacking testosterone from the testes) had no libido, and thus, clinical experience went hand in hand with Beach's experimental demonstration.