Zack is always smiling; as a result, his teachers tend to respond to him in a more pleasant and attentive way. This is an example of a(n)

The primary purpose of a certificate of confidentiality is to: allow law enforcement to investigate abuse cases. protect researchers from disclosing conflicts of interest. prevent subjects from knowing the purpose of a study. protect identifiable research information from compelled disclosure.

The controlled use of fire by hominids: (a) limited the expansion of hominids into certain environments, such as dry grasslands. (b) decreased the amount of food energy available in the hominid diet. (c) contributed to geographical expansion and food production techniques in positive ways. (d) has been shown to contribute little to the digestive process of hominids.

What is the role of communication within groups of people with different backgrounds?