What is the principal zeitgeber for land animals?

According to research conducted by Ridley (1999), how could individuals like Adolph Hitler, serial killer Ted Bundy, and Unabomber Timothy McVeigh commit such acts according to the "nature versus nurture" debate?

a) These individuals were born (nature) to commit such horrendous acts. It was in their genetic makeup. b) Their behaviors are the result of the interaction of nature and nurture. c) These individual's behaviors were attributed to "nurture" and influences of their parents. d) These individuals learned to commit these behaviors after staying in long periods of isolation according to

What is a major limitation of correlational studies?

A) They cannot measure relationships among variables. B) They cannot measure the degree to which a relationship exists between variables. C) They cannot show the direction of a relationship between variables. D) They cannot provide information about causal relationships among variables.