Darrin is a good piano player. when he is alone, his arousal is low and he often gets distracted and makes mistakes. when he is in a recital with strangers, he sometimes gets too nervous and aroused and also makes mistakes. his best performances are typically at home when family and friends are nearby, and his arousal level is moderate. the variations in darrin's performance can be best explained by the:

Yerkes-dodson law      

Explanation:

Yerkes-Dodson law: It was discovered by the renowned psychologists John Dillingham Dodson and Robert Yerkes in 1908.

This law illustrates that there is an association or relation between arousal and performance. The performance of a person decreases when the arousal becomes excessive. In other words, the arousal and performance are directly proportional to each other, so the increase in arousal to an optimal level can increase the performance but if the arousal goes beyond the optimal level then it decreases the performance.

The variations in Darrin's performance can be best explained by the: Yerkes-Dodson law.

the first settlements began along the huang river because of the importance of the huang river in the beginning of china. it goes back to the story, “the tale of emperor yu”, which references the tale of the great flood, which was caused by the huang river and was believed to create and influence china’s making.

i do believe the correct answer is the spread of chinese culture throughout asia and africa.good luck

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