The estimates are called period cohort life expectancies. Because life expectancies worldwide are below 100 years, the term is invariably associated with longevity. Biological influences on lower male life expectancies include genetics and hormones. The two types of expectancies noted are predictive and prescriptive. They have long life expectancies, and high rates of health insurance and regular exercise. Comparing life expectancies from birth across countries can be problematic. Fourteen neighborhoods had lower life expectancies than North Korea. This process will ultimately affect student achievement so that teachers' initial expectancies are confirmed. In the United States, African-American people have shorter life expectancies than their European-American counterparts. However, individuals are unable to explicitly describe what each of these expectancies, or rules, are. The danger of such missions resulted in pioneers having short life expectancies. This designation is granted to global regions that are characterized by the longest life expectancies. Note that life expectancies are not the same at different ages. Polypterids in captivity have life expectancies up to 10 years. EVT proposes that observation and interaction with others leads to expectancies.