These experiments have so many variables that the outcome is sometimes hard to believe (see the section about rats): http://calteches.library.caltech.edu/51/2/

These experiments have so many variables that the outcome is sometimes hard to believe (see the section about rats): http://calteches.library.caltech.edu/51/2/CargoCult.htm http://calteches.library.caltech.edu/51/2/CargoCult.htm Maybe the don't "adjust", but it is a fear reaction because of the imagined proximity of other males, which kind of distracts from the act ... How they measured it? Perhaps a fake female with a reservoir, which would introduce even more variables.