According to , affectionate communication is a biologically adaptive behavior that contributes to human viability and fertility by improving health and fortifying the body’s flight or fight system

The answer is the affective exchange theory.

Explanation:

Affection exchange theory was established in 2001 by Kory Floyd. Floyd states that this theory considers affectionate communication as an adaptive behavior that helps humans to have success in terms of long-term viability.

He also considered that this theory was related to an exchange of affection that was useful in determining if an individual was considered a good prospect concerning parenthood. Floyd also showed the fact that when parents show some kind of affection to their children, they usually have success in reproducing.        

affective exchange theory.

Explanation:

There are many and different ways in which people that are in love shows affection in relationship. One of the ways is known as affectionate communication.

Communication is an important aspect in a healthy relationship, when there is no good Communication, there can not be a good relationship and vice versa.

The theory of affective exchange was proposed by a University Professor that goes by the name Kory Floyd. According to the Professor (Kory Floyd) there are many health benefits of engaging in affectionate communication and one of them is Fertility in human beings.

c. wright mills's sociological imagination suggest investigating to explain this increase?

dude you should crop your image so only the question shows. but   can you explain it better