Final answer:
According to Dr. Joseph LeDoux's research, the boy's initial reaction to the phone ringing is a residual response from the fear-inducing event at school, but he relaxes once he realizes it's just the phone.
Step-by-step explanation:
According to the research of Dr. Joseph LeDoux, the boy's initial reaction to the phone ringing at home can be explained through the concept of alarm reaction and adaptation to stressors. LeDoux's research suggests that when individuals experience a stressful event, such as the loud noise of a fire alarm, their body enters an alarm reaction phase where they may be hyper-reactive to similar stimuli. In this case, the boy's initial startle response to the phone ringing can be seen as a residual reaction from the earlier fear-inducing event at school. However, once he realizes it is just the phone ringing, the boy relaxes as his body adapts to this less intense stressor.