Maternal insulin resistance during late pregnancy is caused by the placental release of ____________

What is one explanation for the peak shift effect?

a. Subjects respond well to rewards in a positive contrast effect. b. Subjects respond to relative values rather than absolute values during discrimination training. c. Subjects respond more intensely when on a multiple schedule of reinforcement. d. Subjects respond more consistently in a negative contrast effect.

In the development of reaching and pushing, which of the following is the earliest behavior likely to be observed?

a. Grasping a moving object b. Holding an object in both hands c. Picking up a piece of yarn using index finger and thumb d. Reaching into a jar to pull out a candy