We see social norms as more relevant when predicting the average behavior of a group, relative to predicting an individual’s behavior:
In judgments of morally relevant behaviors, forecasters estimated that a randomly selected individual (e.g., a student) would act more selflessly (e.g., give to charity) than would the population from which the individual was drawn (e.g., the student body). … When considering how an individual will behave, people give weight to an individual-level force on behavior: what an individual’s moral conscience would lead one to do. When considering a population, forecasters give more emphasis to a group-level force on behavior: social norms and pressures. … Individuals were [also] forecast as more likely than populations to perform behaviors that emerge primarily because of an individual-level force—a person’s will—but not behaviors that are encouraged by social norms. (more)
I agree with Dave on this. There must be an equal contribution from every individual in order to keep a balance.http://www.genericviagra123...
A number of commenters have said something to the effect of "but individuals can be different than the average". Yes, that's true. And the standard deviation reflects how far from the mean we might expect them to be. But we DON'T know in which direction they will deviate from the mean. There is no more reason to believe a random person will be more selfless than average than to believe they will be more selfish. The expected value of their deviation from the average is zero, even if the expected absolute value of said deviation is positive.