"When you're feeling sexual desire for a partner there might be other factors that play into that, for example, how you felt about that partner that day, how attracted you feel to that partner, how attractive you feel to that partner, your relationship and things like that," van Anders said.
[6 Great Things Sex Can Do For You] Solitary desire, on the other hand, may be more internal and less influenced by social factors like relationship satisfaction, she said.
She then compared low-versus-high testosterone participants and their self-reported levels of desire.
In men, she found, levels of testosterone had nothing to do with how much guys thought about sex, solitary or partnered.
The finding bolsters the idea that desire for a partner is more influenced by social factors, van Anders said, while solitary desire is more innate.