Answer:
Confederate.
Step-by-step explanation:
This is explained to be a test of conformity towards or in accordance with human behaviour and it is further explained to be a scenario when someone in secretly seen to be involved directly or indirectly in the said experiment. In many cases, tgere are also groups tagged to be control grouos where also this confedrate presence is not noticed or negligible according to research; thereby taking a toll on the researchers to determine if participants naturally behave that way.