Professor Washington is conducting research into the causes of test anxiety. In order to determine their level of anxiety, she has her participants wear a device that tracks their heart rate variability while they are taking an exam (lower levels of heart rate variability are indicative of higher levels of anxiety). In this research, what is heart rate variability

As nina and erin were eating lunch in the central high school student cafeteria, they were discussing the news coverage about the girls' athletic coach being arrested for selling steroids to student athletes. "i think the guy just did it because they don't pay teachers enough money," nina suggested. "i bet the guy had some other kind of drug addiction he was trying to pay for," erin countered. nina and erin's ideas about the cause of the coach's drug-selling behavior are examples of: