You receive in the mail a great money-saving credit card offer, complete with a rewards program. You read on further to find that the one dollar for every mile flown may not be such a great offer after all, since getting a $500 airline ticket only happens after you acquire 25,000 miles or spend $25,000. This is a ________ schedule.

Research on inmates placed in solitary confinement suggests

that they experience more psychological symptoms, especially mood and anxiety problems, than other inmates. However, this finding may be difficult to interpret because some inmates may be more emotionally maladjusted to begin with. Which of the six principles of scientific thinking does this research finding fit into? A) Extraordinary claims B) Replicability C) Occam's Razor D) Ruling out rival hypotheses

Longitudinal research reveals that the IQ scores of most children __________ during childhood and adolescence

A) fluctuate 10 to 20 points B) increase by about 35 points C) vary by about 50 points D) remain stable