A researcher was interested in the effects of mood on aggression.She decided to see how receiving an insult or a compliment affects aggression, and she measured aggression by having participants administer small shocks to another participant.The researcher found that participants in the insult condition were more aggressive than those in the compliment condition.One of her colleagues reads about this research and voices concern that people in the insult condition may have been more naturally aggressive than people in the compliment condition, causing the differences observed by the researcher.This concern about pre-existing differences between participants in the two conditions would only be valid if

Question

Quizplus · Accepted Answer

Random assignment to conditions helps to ensure that any pre-existing individual differences between participants are evenly distributed across conditions. This makes it less likely that the observed differences between conditions are due to pre-existing differences between individuals. If participants were not randomly assigned to conditions, it would be more likely that the insult condition had more naturally aggressive individuals, which could account for the differences observed in aggression between the two conditions. The other choices are not directly related to the concern raised by the colleague.

A Researcher Was Interested in the Effects of Mood on Aggression.She