In a famous series of experiments conducted by Harry Harlow, infant monkeys were separated from their mothers at birth. The infants were then given two surrogate mothers (a terry-cloth "mother" and a wire "mother"), each of which alternately had a nursing bottle that provided food to the infants. The experimental results showed that in frightening situations, the infant monkeys:

Preferred the terry cloth mother even when the wired mother had the nursing bottle.  

Explanation:

Harry Harlow conducted an experiment on maternal deprivation of the rhesus infants. He separated baby monkeys from their mothers a few hours after birth. He developed two kinds of surrogate monkey mother machines both were equipped to release milk. One of the artificial mothers was prepared using the bare wire mesh and the other was prepared using a soft terry cloth. He observed that because the infants had a choice to choose their artificial mothers they used to spend more time clinging with the terry cloth surrogates although they were obtaining the physical nourishment from the bottles on the bare wire mothers.  

This suggests that attachment of the infant with the terry cloth surrogate was to fulfill the psychological needs of having a mother as every infant requires tender care of a mother after birth.

the factors that the economies of the muslim empires prosper were:

1- land trade routes-located between three continents  

2- sea trade routes

trade contributed to the spread of muslim empires, and with that islamic culture led to a growing feeling of internationalism resulted in the transfer of technology, science, and other cultural forms.

answer; 11th circuit or federal circuit;