In recent years, the difference in intelligence scores between blacks and whites has ______

People with borderline personality disorder are at high risk for _____________________.

Fill in the blank(s) with the appropriate word(s).

LaToya's favorite time of year is Halloween, because she knows that she can go to every house in her neighborhood and get a treat. What reinforcement schedules play a role in LaToya's experience?

a. fixed ratio; fixed time b. variable duration; fixed time c. variable time; variable duration d. fixed interval; variable ratio