Article: “A Scientist’s Gender Biases Mouse Research”
“Duhaime-Ross reports on a new study, which found that mice are scared of men. When a male researcher works with a mouse, the mouse’s body courses with stress hormones. This doesn’t happen when a woman scientist is doing the work. The difference in how mice respond to male and female researchers could potentially skew everything from behavioral studies to cell research.” https://www.smithsonianmag.com/smart-news/scientists-gender-biases-mouse-research-180951240/
This real-life example shows an unintended effect of “direct experience. ” In this case the presence (and gender) of scientists may have affected the outcomes the experiment.