Plasma Testosterone Levels in the Male Rhesus: Influences of Sexual and Social Stimuli

TLDR

Four adult male rhesus monkeys were individually exposed to receptive females, then subjected to defeat by a large all‑male group, and later reintroduced to females. Dominance behavior and frequent copulations were observed, with plasma testosterone rising two‑to‑threefold during female exposure, falling after defeat, and rapidly returning to elevated levels upon re‑exposure.

Abstract

Four adult male rhesus monkeys were provided access individually to a group of receptive females. Each male assumed dominance and engaged in frequent copulations. Plasma testosterone levels increased two- to threefold during this period. Next, each male was subjected to sudden and decisive defeat by a large all-male group, and plasma testosterone fell following this experience. Two males were later reintroduced to the females, and plasma testosterone rose rapidly to the previous elevated levels.