Final answer:
Dan likely wasted effort in gathering 100 tattooed fraternity members to persuade Roger to get a tattoo because individual choices are often influenced by personal factors which can outweigh the influence of group pressure or the bandwagon effect.
Step-by-step explanation:
In an attempt to persuade Roger to get a fraternity tattoo on his arm, Dan assembled 100 tattooed fraternity members. Dan probably wasted a lot of effort in doing so because this approach relies on the assumption that seeing a large number of people who have made a certain choice will necessarily persuade an individual to make the same choice. This is known as the bandwagon effect, a type of groupthink or peer pressure.
However, individual decisions, especially those regarding permanent body modifications like tattoos, can be heavily influenced by personal beliefs, values, and concerns about future consequences. These personal factors may surpass any persuasive power herd mentality might have, making the extensive effort less effective.