Before we know what differences between typical male and typical female brains mean, we need research that looks for links between these brain differences and _____

One of the main problems associated with research with psychiatric populations is that

a. they are so different from one another that it is ethically troublesome to put them in treatments that are standardized rather than individualized. b. they may not be able to give truly informed consent because of their psychiatric problems. c. such research has to involve placebo groups for whom treatment is withheld. d. outside, pharmaceutical companies may provide funding.

An axon's length can range from a few millimeters to

a. 1 inch. c. several feet. b. 12 inches. d. up to a mile.