Final answer:
It is true that merely thinking about potential sexual activity can result in hormonal changes within the body, influenced by the hypothalamus and circulating levels of sex hormones like testosterone.
Step-by-step explanation:
The statement that just thinking about the prospect of having sex can cause changes in hormone levels is true. The hypothalamus, which oversees endocrine functions related to sexual behavior and motivation, can respond to sexual thoughts by influencing hormone levels. Sex hormones play a significant role in influencing sexual motivation for all genders and may vary with changes in circulating testosterone. Moreover, anticipating sexual activity can lead to physiological responses, similar to other emotional or psychological stimuli that impact hormonal levels.