According to the biosocial perspective, in a hostile and unpredictable environment, what should we expect to see in fertility rates?

The answer is "Fertility rates increase, meaning more children per family".

New theoretical models conceptualize families as frameworks influenced by, and affecting change in, proportional impacts among social, conduct, and natural procedures. Mechanical leaps forward make noninvasive appraisal of numerous natural procedures accessible to family scientists. These hypothetical and estimation propels have brought about huge increments in investigate on family procedures and connections that coordinate information from the fields of conduct endocrinology, conduct hereditary qualities, and, to a lesser degree, developmental psychology.