In the context of the influences on aggression, which of the following has NOT been linked with aggressive behavior?

One has to be cautious about concluding that a "fighting spirit" helps one cope with stress and survive cancer because:

a. Physiological mechanisms are rarely assessed in these studies b. Studies looking at these variables have found mostly negative results c. The only research done in this area has been done with nonhumans d. The studies involve cancers that are in the early stages

In males, some degree of penile erection usually occurs during

A) sex-related dreams. B) dreams with no sexual content. C) REM sleep. D) all of the above E) both A and C