Certain kinds of fish can change their sex in response to social conditions. Certain human being may appear to change sex when they mature. Describe what alcohol does in the brain and genetic studies on alcoholism. Describe the mechanisms of sleep and dreaming. Stay away from psychological interpretations of dreams unless they are relevant to the physiology.
People seem to learn to speak almost without effort.
Describe the anatomy and physiology of speech. Describe the physiology of the stress reaction.