I intend to subject participants to a within subject manipulation having two levels. Then, I want to measure the effect of that manipulation controlling for individual differences.
For between group designs, dictator,ultimatum (one-shot) or donation to charities are great. However, they cannot be asked again if i need to run the experiment as a within-subject one.
Could you suggest which measure (dependent variable) would allow me to see whether priming a variable (say music [Sad/Neutral]) in a within-subject design affects prosocial behavior?