recognizing and reacting to individuals based on group affiliation was probably a very important skill for early hunter–gatherers, whose survival often depended on quickly identifying others as potential friends or foes. this categorization was made primarily on the basis of

According to ohrp, a problem is an “unanticipated problem” when it meets which of the following criteria: unexpected, related or possibly related to the research, suggests that the research does not put the subjects or others at greater riskunexpected, related or possible related to the research, suggests the research puts subjects or others at greater riskunexpected, unrelated to the research but still occurring with a subject, suggests the research puts others at greater riskexpected, related or possible related to the research, suggests the research puts others at greater risk